diff --git a/core/modules/field/field.attach.inc b/core/modules/field/field.attach.inc
index baa7ff4..6fd3e36 100644
--- a/core/modules/field/field.attach.inc
+++ b/core/modules/field/field.attach.inc
@@ -1610,7 +1610,7 @@ function field_entity_bundle_delete($entity_type, $bundle) {
   // entity types or bundles.
   $instances = field_read_instances(array('entity_type' => $entity_type, 'bundle' => $bundle), array('include_inactive' => TRUE));
   foreach ($instances as $instance) {
-    field_delete_instance($instance);
+    $instance->delete();
   }
 
   // Clear the cache.
diff --git a/core/modules/field/field.module b/core/modules/field/field.module
index 798d604..bc90be4 100644
--- a/core/modules/field/field.module
+++ b/core/modules/field/field.module
@@ -74,8 +74,7 @@
  *   field_sql_storage.module, stores field data in the local SQL database.
  *
  * - @link field_purge Field API bulk data deletion @endlink: Cleans up after
- *   bulk deletion operations such as field_delete_field() and
- *   field_delete_instance().
+ *   bulk deletion operations such as deletion of field or field_instance.
  *
  * - @link field_language Field language API @endlink: Provides native
  *   multilingual support for the Field API.
diff --git a/core/modules/field/lib/Drupal/field/Tests/ActiveTest.php b/core/modules/field/lib/Drupal/field/Tests/ActiveTest.php
index c555dc8..c74d426 100644
--- a/core/modules/field/lib/Drupal/field/Tests/ActiveTest.php
+++ b/core/modules/field/lib/Drupal/field/Tests/ActiveTest.php
@@ -37,7 +37,7 @@ function testActive() {
         'type' => 'field_sql_storage',
       ),
     );
-    field_create_field($field_definition);
+    entity_create('field_entity', $field_definition)->save();
 
     // Test disabling and enabling:
     // - the field type module,
diff --git a/core/modules/field/lib/Drupal/field/Tests/BulkDeleteTest.php b/core/modules/field/lib/Drupal/field/Tests/BulkDeleteTest.php
index d27bd7d..88b7798 100644
--- a/core/modules/field/lib/Drupal/field/Tests/BulkDeleteTest.php
+++ b/core/modules/field/lib/Drupal/field/Tests/BulkDeleteTest.php
@@ -104,10 +104,18 @@ function setUp() {
     }
 
     // Create two fields.
-    $field = array('field_name' => 'bf_1', 'type' => 'test_field', 'cardinality' => 1);
-    $this->fields[] = field_create_field($field);
-    $field = array('field_name' => 'bf_2', 'type' => 'test_field', 'cardinality' => 4);
-    $this->fields[] = field_create_field($field);
+    $this->fields[] = $field = entity_create('field_entity', array(
+      'field_name' => 'bf_1',
+      'type' => 'test_field',
+      'cardinality' => 1
+    ));
+    $field->save();
+    $this->fields[] = $field = entity_create('field_entity', array(
+      'field_name' => 'bf_2',
+      'type' => 'test_field',
+      'cardinality' => 4
+    ));
+    $field->save();
 
     // For each bundle, create an instance of each field, and 10
     // entities with values for each field.
@@ -115,18 +123,18 @@ function setUp() {
     $this->entity_type = 'test_entity';
     foreach ($this->bundles as $bundle) {
       foreach ($this->fields as $field) {
-        $instance = array(
-          'field_name' => $field['field_name'],
+        $this->instances[] = $instance = entity_create('field_instance', array(
+          'field_name' => $field->id(),
           'entity_type' => $this->entity_type,
           'bundle' => $bundle,
-        );
-        $this->instances[] = field_create_instance($instance);
+        ));
+        $instance->save();
       }
 
       for ($i = 0; $i < 10; $i++) {
         $entity = field_test_create_entity($id, $id, $bundle);
         foreach ($this->fields as $field) {
-          $entity->{$field['field_name']}[Language::LANGCODE_NOT_SPECIFIED] = $this->_generateTestFieldValues($field['cardinality']);
+          $entity->{$field->id()}[Language::LANGCODE_NOT_SPECIFIED] = $this->_generateTestFieldValues($field->cardinality);
         }
         $entity->save();
         $id++;
@@ -144,14 +152,13 @@ function setUp() {
    * the database and that the appropriate Field API functions can
    * operate on the deleted data and instance.
    *
-   * This tests how EntityFieldQuery interacts with
-   * field_delete_instance() and could be moved to FieldCrudTestCase,
-   * but depends on this class's setUp().
+   * This tests how EntityFieldQuery interacts with field instance deletion and
+   * could be moved to FieldCrudTestCase, but depends on this class's setUp().
    */
   function testDeleteFieldInstance() {
     $bundle = reset($this->bundles);
     $field = reset($this->fields);
-    $field_name = $field['field_name'];
+    $field_name = $field->id();
     $factory = \Drupal::service('entity.query');
 
     // There are 10 entities of this bundle.
@@ -161,11 +168,11 @@ function testDeleteFieldInstance() {
     $this->assertEqual(count($found), 10, 'Correct number of entities found before deleting');
 
     // Delete the instance.
-    $instance = field_info_instance($this->entity_type, $field['field_name'], $bundle);
-    field_delete_instance($instance);
+    $instance = field_info_instance($this->entity_type, $field->id(), $bundle);
+    $instance->delete();
 
     // The instance still exists, deleted.
-    $instances = field_read_instances(array('field_id' => $field['uuid'], 'deleted' => TRUE), array('include_deleted' => TRUE, 'include_inactive' => TRUE));
+    $instances = field_read_instances(array('field_id' => $field->id(), 'deleted' => TRUE), array('include_deleted' => TRUE, 'include_inactive' => TRUE));
     $this->assertEqual(count($instances), 1, 'There is one deleted instance');
     $this->assertEqual($instances[0]['bundle'], $bundle, 'The deleted instance is for the correct bundle');
 
@@ -192,10 +199,10 @@ function testDeleteFieldInstance() {
       $ids->entity_id = $entity_id;
       $entities[$entity_id] = _field_create_entity_from_ids($ids);
     }
-    field_attach_load($this->entity_type, $entities, FIELD_LOAD_CURRENT, array('field_id' => $field['uuid'], 'deleted' => TRUE));
+    field_attach_load($this->entity_type, $entities, FIELD_LOAD_CURRENT, array('field_id' => $field->uuid, 'deleted' => TRUE));
     $this->assertEqual(count($found), 10, 'Correct number of entities found after deleting');
     foreach ($entities as $id => $entity) {
-      $this->assertEqual($this->entities[$id]->{$field['field_name']}, $entity->{$field['field_name']}, "Entity $id with deleted data loaded correctly");
+      $this->assertEqual($this->entities[$id]->{$field->id()}, $entity->{$field->id()}, "Entity $id with deleted data loaded correctly");
     }
   }
 
@@ -211,8 +218,8 @@ function testPurgeInstance() {
     $field = reset($this->fields);
 
     // Delete the instance.
-    $instance = field_info_instance($this->entity_type, $field['field_name'], $bundle);
-    field_delete_instance($instance);
+    $instance = field_info_instance($this->entity_type, $field->id(), $bundle);
+    $instance->delete();
 
     // No field hooks were called.
     $mem = field_test_memorize();
@@ -226,7 +233,7 @@ function testPurgeInstance() {
       // There are $count deleted entities left.
       $found = \Drupal::entityQuery('test_entity')
         ->condition('fttype', $bundle)
-        ->condition($field['field_name'] . '.deleted', 1)
+        ->condition($field->id() . '.deleted', 1)
         ->execute();
       $this->assertEqual(count($found), $count, 'Correct number of entities found after purging 2');
     }
@@ -238,7 +245,7 @@ function testPurgeInstance() {
     // bundle.
     $actual_hooks = field_test_memorize();
     $hooks = array();
-    $entities = $this->convertToPartialEntities($this->entities_by_bundles[$bundle], $field['field_name']);
+    $entities = $this->convertToPartialEntities($this->entities_by_bundles[$bundle], $field->id());
     foreach (array_chunk($entities, $batch_size, TRUE) as $chunk_entity) {
       $hooks['field_test_field_load'][] = $chunk_entity;
     }
@@ -248,19 +255,19 @@ function testPurgeInstance() {
     $this->checkHooksInvocations($hooks, $actual_hooks);
 
     // The instance still exists, deleted.
-    $instances = field_read_instances(array('field_id' => $field['uuid'], 'deleted' => TRUE), array('include_deleted' => TRUE, 'include_inactive' => TRUE));
+    $instances = field_read_instances(array('field_id' => $field->uuid, 'deleted' => TRUE), array('include_deleted' => TRUE, 'include_inactive' => TRUE));
     $this->assertEqual(count($instances), 1, 'There is one deleted instance');
 
     // Purge the instance.
     field_purge_batch($batch_size);
 
     // The instance is gone.
-    $instances = field_read_instances(array('field_id' => $field['uuid'], 'deleted' => TRUE), array('include_deleted' => TRUE, 'include_inactive' => TRUE));
+    $instances = field_read_instances(array('field_id' => $field->uuid, 'deleted' => TRUE), array('include_deleted' => TRUE, 'include_inactive' => TRUE));
     $this->assertEqual(count($instances), 0, 'The instance is gone');
 
     // The field still exists, not deleted, because it has a second instance.
-    $fields = field_read_fields(array('uuid' => $field['uuid']), array('include_deleted' => TRUE, 'include_inactive' => TRUE));
-    $this->assertTrue(isset($fields[$field['uuid']]), 'The field exists and is not deleted');
+    $fields = field_read_fields(array('uuid' => $field->uuid), array('include_deleted' => TRUE, 'include_inactive' => TRUE));
+    $this->assertTrue(isset($fields[$field->uuid]), 'The field exists and is not deleted');
   }
 
   /**
@@ -275,8 +282,8 @@ function testPurgeField() {
 
     // Delete the first instance.
     $bundle = reset($this->bundles);
-    $instance = field_info_instance($this->entity_type, $field['field_name'], $bundle);
-    field_delete_instance($instance);
+    $instance = field_info_instance($this->entity_type, $field->id(), $bundle);
+    $instance->delete();
 
     // Assert that hook_field_delete() was not called yet.
     $mem = field_test_memorize();
@@ -292,7 +299,7 @@ function testPurgeField() {
     // bundle.
     $actual_hooks = field_test_memorize();
     $hooks = array();
-    $entities = $this->convertToPartialEntities($this->entities_by_bundles[$bundle], $field['field_name']);
+    $entities = $this->convertToPartialEntities($this->entities_by_bundles[$bundle], $field->id());
     $hooks['field_test_field_load'][] = $entities;
     $hooks['field_test_field_delete'] = $entities;
     $this->checkHooksInvocations($hooks, $actual_hooks);
@@ -301,13 +308,13 @@ function testPurgeField() {
     field_purge_batch(0);
 
     // The field still exists, not deleted.
-    $fields = field_read_fields(array('uuid' => $field['uuid']), array('include_deleted' => TRUE));
-    $this->assertTrue(isset($fields[$field['uuid']]) && !$fields[$field['uuid']]->deleted, 'The field exists and is not deleted');
+    $fields = field_read_fields(array('uuid' => $field->uuid), array('include_deleted' => TRUE));
+    $this->assertTrue(isset($fields[$field->uuid]) && !$fields[$field->uuid]->deleted, 'The field exists and is not deleted');
 
     // Delete the second instance.
     $bundle = next($this->bundles);
-    $instance = field_info_instance($this->entity_type, $field['field_name'], $bundle);
-    field_delete_instance($instance);
+    $instance = field_info_instance($this->entity_type, $field->id(), $bundle);
+    $instance->delete();
 
     // Assert that hook_field_delete() was not called yet.
     $mem = field_test_memorize();
@@ -319,20 +326,20 @@ function testPurgeField() {
     // Check hooks invocations (same as above, for the 2nd bundle).
     $actual_hooks = field_test_memorize();
     $hooks = array();
-    $entities = $this->convertToPartialEntities($this->entities_by_bundles[$bundle], $field['field_name']);
+    $entities = $this->convertToPartialEntities($this->entities_by_bundles[$bundle], $field->id());
     $hooks['field_test_field_load'][] = $entities;
     $hooks['field_test_field_delete'] = $entities;
     $this->checkHooksInvocations($hooks, $actual_hooks);
 
     // The field still exists, deleted.
-    $fields = field_read_fields(array('uuid' => $field['uuid']), array('include_deleted' => TRUE));
-    $this->assertTrue(isset($fields[$field['uuid']]) && $fields[$field['uuid']]->deleted, 'The field exists and is deleted');
+    $fields = field_read_fields(array('uuid' => $field->uuid), array('include_deleted' => TRUE));
+    $this->assertTrue(isset($fields[$field->uuid]) && $fields[$field->uuid]->deleted, 'The field exists and is deleted');
 
     // Purge again to purge the instance and the field.
     field_purge_batch(0);
 
     // The field is gone.
-    $fields = field_read_fields(array('uuid' => $field['uuid']), array('include_deleted' => TRUE, 'include_inactive' => TRUE));
+    $fields = field_read_fields(array('uuid' => $field->uuid), array('include_deleted' => TRUE, 'include_inactive' => TRUE));
     $this->assertEqual(count($fields), 0, 'The field is purged.');
   }
 }
diff --git a/core/modules/field/lib/Drupal/field/Tests/CrudTest.php b/core/modules/field/lib/Drupal/field/Tests/CrudTest.php
index 7960f82..bdd71ca 100644
--- a/core/modules/field/lib/Drupal/field/Tests/CrudTest.php
+++ b/core/modules/field/lib/Drupal/field/Tests/CrudTest.php
@@ -41,7 +41,8 @@ function testCreateField() {
       'type' => 'test_field',
     );
     field_test_memorize();
-    $field = field_create_field($field_definition);
+    $field = entity_create('field_entity', $field_definition);
+    $field->save();
     $mem = field_test_memorize();
     $this->assertIdentical($mem['field_test_field_create_field'][0][0]['field_name'], $field_definition['field_name'], 'hook_field_create_field() called with correct arguments.');
     $this->assertIdentical($mem['field_test_field_create_field'][0][0]['type'], $field_definition['type'], 'hook_field_create_field() called with correct arguments.');
@@ -67,7 +68,7 @@ function testCreateField() {
 
     // Guarantee that the name is unique.
     try {
-      field_create_field($field_definition);
+      entity_create('field_entity', $field_definition)->save();
       $this->fail(t('Cannot create two fields with the same name.'));
     }
     catch (FieldException $e) {
@@ -79,7 +80,7 @@ function testCreateField() {
       $field_definition = array(
         'field_name' => 'field_1',
       );
-      field_create_field($field_definition);
+      entity_create('field_entity', $field_definition)->save();
       $this->fail(t('Cannot create a field with no type.'));
     }
     catch (FieldException $e) {
@@ -91,7 +92,7 @@ function testCreateField() {
       $field_definition = array(
         'type' => 'test_field'
       );
-      field_create_field($field_definition);
+      entity_create('field_entity', $field_definition)->save();
       $this->fail(t('Cannot create an unnamed field.'));
     }
     catch (FieldException $e) {
@@ -104,7 +105,7 @@ function testCreateField() {
         'field_name' => '2field_2',
         'type' => 'test_field',
       );
-      field_create_field($field_definition);
+      entity_create('field_entity', $field_definition)->save();
       $this->fail(t('Cannot create a field with a name starting with a digit.'));
     }
     catch (FieldException $e) {
@@ -117,7 +118,7 @@ function testCreateField() {
         'field_name' => 'field#_3',
         'type' => 'test_field',
       );
-      field_create_field($field_definition);
+      entity_create('field_entity', $field_definition)->save();
       $this->fail(t('Cannot create a field with a name containing an illegal character.'));
     }
     catch (FieldException $e) {
@@ -130,7 +131,7 @@ function testCreateField() {
         'field_name' => '_12345678901234567890123456789012',
         'type' => 'test_field',
       );
-      field_create_field($field_definition);
+      entity_create('field_entity', $field_definition)->save();
       $this->fail(t('Cannot create a field with a name longer than 32 characters.'));
     }
     catch (FieldException $e) {
@@ -144,7 +145,7 @@ function testCreateField() {
         'type' => 'test_field',
         'field_name' => 'ftvid',
       );
-      field_create_field($field_definition);
+      entity_create('field_entity', $field_definition)->save();
       $this->fail(t('Cannot create a field bearing the name of an entity key.'));
     }
     catch (FieldException $e) {
@@ -165,7 +166,7 @@ function testCreateFieldFail() {
 
     // Try to create the field.
     try {
-      $field = field_create_field($field_definition);
+      entity_create('field_entity', $field_definition)->save();
       $this->assertTrue(FALSE, 'Field creation (correctly) fails.');
     }
     catch (\Exception $e) {
@@ -185,7 +186,7 @@ function testReadField() {
       'field_name' => 'field_1',
       'type' => 'test_field',
     );
-    field_create_field($field_definition);
+    entity_create('field_entity', $field_definition)->save();
 
     // Read the field back.
     $field = field_read_field($field_definition['field_name']);
@@ -200,7 +201,7 @@ function testReadFields() {
       'field_name' => 'field_1',
       'type' => 'test_field',
     );
-    field_create_field($field_definition);
+    entity_create('field_entity', $field_definition)->save();
 
     // Check that 'single column' criteria works.
     $fields = field_read_fields(array('field_name' => $field_definition['field_name']));
@@ -218,7 +219,7 @@ function testReadFields() {
       'entity_type' => 'test_entity',
       'bundle' => 'test_bundle',
     );
-    field_create_instance($instance_definition);
+    entity_create('field_instance', $instance_definition)->save();
   }
 
   /**
@@ -230,7 +231,7 @@ function testFieldIndexes() {
       'field_name' => 'field_1',
       'type' => 'test_field',
     );
-    field_create_field($field_definition);
+    entity_create('field_entity', $field_definition)->save();
     $field = field_read_field($field_definition['field_name']);
     $schema = $field->getSchema();
     $expected_indexes = array('value' => array('value'));
@@ -245,7 +246,7 @@ function testFieldIndexes() {
         'value' => array(),
       ),
     );
-    field_create_field($field_definition);
+    entity_create('field_entity', $field_definition)->save();
     $field = field_read_field($field_definition['field_name']);
     $schema = $field->getSchema();
     $expected_indexes = array('value' => array());
@@ -260,7 +261,7 @@ function testFieldIndexes() {
         'value_2' => array('value'),
       ),
     );
-    field_create_field($field_definition);
+    entity_create('field_entity', $field_definition)->save();
     $field = field_read_field($field_definition['field_name']);
     $schema = $field->getSchema();
     $expected_indexes = array('value' => array('value'), 'value_2' => array('value'));
@@ -275,9 +276,9 @@ function testDeleteField() {
 
     // Create two fields (so we can test that only one is deleted).
     $this->field = array('field_name' => 'field_1', 'type' => 'test_field');
-    field_create_field($this->field);
+    entity_create('field_entity', $this->field)->save();
     $this->another_field = array('field_name' => 'field_2', 'type' => 'test_field');
-    field_create_field($this->another_field);
+    entity_create('field_entity', $this->another_field)->save();
 
     // Create instances for each.
     $this->instance_definition = array(
@@ -285,15 +286,15 @@ function testDeleteField() {
       'entity_type' => 'test_entity',
       'bundle' => 'test_bundle',
     );
-    field_create_instance($this->instance_definition);
-    $this->another_instance_definition = $this->instance_definition;
-    $this->another_instance_definition['field_name'] = $this->another_field['field_name'];
-    field_create_instance($this->another_instance_definition);
+    entity_create('field_instance', $this->instance_definition)->save();
+    $another_instance_definition = $this->instance_definition;
+    $another_instance_definition['field_name'] = $this->another_field['field_name'];
+    entity_create('field_instance', $another_instance_definition)->save();
 
     // Test that the first field is not deleted, and then delete it.
     $field = field_read_field($this->field['field_name'], array('include_deleted' => TRUE));
     $this->assertTrue(!empty($field) && empty($field['deleted']), 'A new field is not marked for deletion.');
-    field_delete_field($this->field['field_name']);
+    field_info_field($this->field['field_name'])->delete();
 
     // Make sure that the field is marked as deleted when it is specifically
     // loaded.
@@ -316,13 +317,13 @@ function testDeleteField() {
     // Make sure the other field (and its field instance) are not deleted.
     $another_field = field_read_field($this->another_field['field_name']);
     $this->assertTrue(!empty($another_field) && empty($another_field['deleted']), 'A non-deleted field is not marked for deletion.');
-    $another_instance = field_read_instance('test_entity', $this->another_instance_definition['field_name'], $this->another_instance_definition['bundle']);
+    $another_instance = field_read_instance('test_entity', $another_instance_definition['field_name'], $another_instance_definition['bundle']);
     $this->assertTrue(!empty($another_instance) && empty($another_instance['deleted']), 'An instance of a non-deleted field is not marked for deletion.');
 
     // Try to create a new field the same name as a deleted field and
     // write data into it.
-    field_create_field($this->field);
-    field_create_instance($this->instance_definition);
+    entity_create('field_entity', $this->field)->save();
+    entity_create('field_instance', $this->instance_definition)->save();
     $field = field_read_field($this->field['field_name']);
     $this->assertTrue(!empty($field) && empty($field['deleted']), 'A new field with a previously used name is created.');
     $instance = field_read_instance('test_entity', $this->instance_definition['field_name'], $this->instance_definition['bundle']);
@@ -346,12 +347,13 @@ function testDeleteField() {
   }
 
   function testUpdateFieldType() {
-    $field = array('field_name' => 'field_type', 'type' => 'number_decimal');
-    $field = field_create_field($field);
+    $field_definition = array('field_name' => 'field_type', 'type' => 'number_decimal');
+    $field = entity_create('field_entity', $field_definition);
+    $field->save();
 
-    $test_field = array('field_name' => 'field_type', 'type' => 'number_integer');
     try {
-      field_update_field($test_field);
+      $field->type = 'number_integer';
+      $field->save();
       $this->fail(t('Cannot update a field to a different type.'));
     }
     catch (FieldException $e) {
@@ -367,21 +369,23 @@ function testUpdateField() {
     // respected. Since cardinality enforcement is consistent across database
     // systems, it makes a good test case.
     $cardinality = 4;
-    $field = field_create_field(array(
+    $field = entity_create('field_entity', array(
       'field_name' => 'field_update',
       'type' => 'test_field',
       'cardinality' => $cardinality,
     ));
-    $instance = field_create_instance(array(
+    $field->save();
+    $instance = entity_create('field_instance', array(
       'field_name' => 'field_update',
       'entity_type' => 'test_entity',
       'bundle' => 'test_bundle',
     ));
+    $instance->save();
 
     do {
       // We need a unique ID for our entity. $cardinality will do.
       $id = $cardinality;
-      $entity = field_test_create_entity($id, $id, $instance['bundle']);
+      $entity = field_test_create_entity($id, $id, $instance->bundle);
       // Fill in the entity with more values than $cardinality.
       for ($i = 0; $i < 20; $i++) {
         $entity->field_update[Language::LANGCODE_NOT_SPECIFIED][$i]['value'] = $i;
@@ -389,16 +393,16 @@ function testUpdateField() {
       // Save the entity.
       field_attach_insert($entity);
       // Load back and assert there are $cardinality number of values.
-      $entity = field_test_create_entity($id, $id, $instance['bundle']);
+      $entity = field_test_create_entity($id, $id, $instance->bundle);
       field_attach_load('test_entity', array($id => $entity));
-      $this->assertEqual(count($entity->field_update[Language::LANGCODE_NOT_SPECIFIED]), $field['cardinality'], 'Cardinality is kept');
+      $this->assertEqual(count($entity->field_update[Language::LANGCODE_NOT_SPECIFIED]), $field->cardinality, 'Cardinality is kept');
       // Now check the values themselves.
       for ($delta = 0; $delta < $cardinality; $delta++) {
         $this->assertEqual($entity->field_update[Language::LANGCODE_NOT_SPECIFIED][$delta]['value'], $delta, 'Value is kept');
       }
       // Increase $cardinality and set the field cardinality to the new value.
-      $field['cardinality'] = ++$cardinality;
-      field_update_field($field);
+      $field->cardinality = ++$cardinality;
+      $field->save();
     } while ($cardinality < 6);
   }
 
@@ -406,19 +410,25 @@ function testUpdateField() {
    * Test field type modules forbidding an update.
    */
   function testUpdateFieldForbid() {
-    $field = array('field_name' => 'forbidden', 'type' => 'test_field', 'settings' => array('changeable' => 0, 'unchangeable' => 0));
-    $field = field_create_field($field);
-    $field['settings']['changeable']++;
+    $field = entity_create('field_entity', array(
+      'field_name' => 'forbidden',
+      'type' => 'test_field',
+      'settings' => array(
+        'changeable' => 0,
+        'unchangeable' => 0
+    ));
+    $field->save();
+    $field->settings['changeable']++;
     try {
-      field_update_field($field);
+      $field->save();
       $this->pass(t("A changeable setting can be updated."));
     }
     catch (FieldException $e) {
       $this->fail(t("An unchangeable setting cannot be updated."));
     }
-    $field['settings']['unchangeable']++;
+    $field->settings['unchangeable']++;
     try {
-      field_update_field($field);
+      $field->save();
       $this->fail(t("An unchangeable setting can be updated."));
     }
     catch (FieldException $e) {
diff --git a/core/modules/field/lib/Drupal/field/Tests/DisplayApiTest.php b/core/modules/field/lib/Drupal/field/Tests/DisplayApiTest.php
index 9ca988e..aaec563 100644
--- a/core/modules/field/lib/Drupal/field/Tests/DisplayApiTest.php
+++ b/core/modules/field/lib/Drupal/field/Tests/DisplayApiTest.php
@@ -54,8 +54,8 @@ function setUp() {
       ),
     );
 
-    field_create_field($this->field);
-    field_create_instance($this->instance);
+    entity_create('field_entity', $this->field)->save();
+    entity_create('field_instance', $this->instance)->save();
     // Create a display for the default view mode.
     entity_get_display($this->instance['entity_type'], $this->instance['bundle'], 'default')
       ->setComponent($this->field_name, $this->display_options['default'])
diff --git a/core/modules/field/lib/Drupal/field/Tests/FieldAccessTest.php b/core/modules/field/lib/Drupal/field/Tests/FieldAccessTest.php
index b63d48d..3416f31 100644
--- a/core/modules/field/lib/Drupal/field/Tests/FieldAccessTest.php
+++ b/core/modules/field/lib/Drupal/field/Tests/FieldAccessTest.php
@@ -41,13 +41,13 @@ function setUp() {
       'field_name' => 'test_view_field',
       'type' => 'text',
     );
-    field_create_field($this->field);
+    entity_create('field_entity', $this->field)->save();
     $this->instance = array(
       'field_name' => $this->field['field_name'],
       'entity_type' => 'node',
       'bundle' => $this->content_type,
     );
-    field_create_instance($this->instance);
+    entity_create('field_instance', $this->instance)->save();
 
     // Assign display properties for the 'default' and 'teaser' view modes.
     foreach (array('default', 'teaser') as $view_mode) {
diff --git a/core/modules/field/lib/Drupal/field/Tests/FieldAttachOtherTest.php b/core/modules/field/lib/Drupal/field/Tests/FieldAttachOtherTest.php
index d16b25a..e795a5a 100644
--- a/core/modules/field/lib/Drupal/field/Tests/FieldAttachOtherTest.php
+++ b/core/modules/field/lib/Drupal/field/Tests/FieldAttachOtherTest.php
@@ -192,9 +192,10 @@ function testFieldAttachPrepareViewMultiple() {
     // hook_field_formatter_prepare_view().
     field_test_create_bundle('test_bundle_2');
     $formatter_setting = $this->randomName();
-    $this->instance2 = $this->instance;
-    $this->instance2['bundle'] = 'test_bundle_2';
-    field_create_instance($this->instance2);
+    $instance_definition = $this->instance_definition;
+    $instance_definition['bundle'] = 'test_bundle_2';
+    $this->instance2 = entity_create('field_instance', $instance_definition);
+    $this->instance2->save();
 
     $display_2 = entity_get_display('test_entity', 'test_bundle_2', 'full')
       ->setComponent($this->field['field_name'], array(
@@ -268,9 +269,9 @@ function testFieldAttachCache() {
       'fttype' => $this->instance['bundle'],
     ));
     $cid = "field:$entity_type:{$entity_init->ftid}";
-    $instance = $this->instance;
-    $instance['entity_type'] = $entity_type;
-    field_create_instance($instance);
+    $instance_definition = $this->instance_definition;
+    $instance_definition['entity_type'] = $entity_type;
+    entity_create('field_instance', $instance_definition)->save();
 
     // Check that no initial cache entry is present.
     $this->assertFalse(cache('field')->get($cid), 'Cached: no initial cache entry');
diff --git a/core/modules/field/lib/Drupal/field/Tests/FieldAttachStorageTest.php b/core/modules/field/lib/Drupal/field/Tests/FieldAttachStorageTest.php
index 7192067..0e46e15 100644
--- a/core/modules/field/lib/Drupal/field/Tests/FieldAttachStorageTest.php
+++ b/core/modules/field/lib/Drupal/field/Tests/FieldAttachStorageTest.php
@@ -16,6 +16,14 @@
  * all hook_field_attach_pre_{load,insert,update}() hooks.
  */
 class FieldAttachStorageTest extends FieldUnitTestBase {
+
+  /**
+   * The field instance.
+   *
+   * @var \Drupal\field\Plugin\Core\Entity\FieldInstance
+   */
+  protected $instance;
+
   public static function getInfo() {
     return array(
       'name' => 'Field attach tests (storage-related)',
@@ -39,7 +47,7 @@ function testFieldAttachSaveLoad() {
     // Configure the instance so that we test hook_field_load() (see
     // field_test_field_load() in field_test.module).
     $this->instance['settings']['test_hook_field_load'] = TRUE;
-    field_update_instance($this->instance);
+    $this->instance->save();
     $langcode = Language::LANGCODE_NOT_SPECIFIED;
 
     $entity_type = 'test_entity';
@@ -117,11 +125,11 @@ function testFieldAttachLoadMultiple() {
     );
     for ($i = 1; $i <= 3; $i++) {
       $field_names[$i] = 'field_' . $i;
-      $field = array('field_name' => $field_names[$i], 'type' => 'test_field');
-      $field = field_create_field($field);
+      $field = entity_create('field_entity', array('field_name' => $field_names[$i], 'type' => 'test_field'));
+      $field->save();
       $field_ids[$i] = $field['uuid'];
       foreach ($field_bundles_map[$i] as $bundle) {
-        $instance = array(
+        entity_create('field_instance', array(
           'field_name' => $field_names[$i],
           'entity_type' => 'test_entity',
           'bundle' => $bundles[$bundle],
@@ -130,8 +138,7 @@ function testFieldAttachLoadMultiple() {
             // (see field_test_field_load() in field_test.module).
             'test_hook_field_load' => TRUE,
           ),
-        );
-        field_create_instance($instance);
+        ))->save();
       }
     }
 
@@ -191,13 +198,13 @@ function testFieldAttachSaveLoadDifferentStorage() {
       ),
     );
     foreach ($fields as $field) {
-      field_create_field($field);
+      entity_create('field_entity', $field)->save();
       $instance = array(
         'field_name' => $field['field_name'],
         'entity_type' => 'test_entity',
         'bundle' => 'test_bundle',
       );
-      field_create_instance($instance);
+      entity_create('field_instance', $instance)->save();
     }
 
     $entity_init = field_test_create_entity();
@@ -226,22 +233,19 @@ function testFieldAttachSaveLoadDifferentStorage() {
    */
   function testFieldStorageDetailsAlter() {
     $field_name = 'field_test_change_my_details';
-    $field = array(
+    $field = entity_create('field_entity', array(
       'field_name' => $field_name,
       'type' => 'test_field',
       'cardinality' => 4,
       'storage' => array('type' => 'field_test_storage'),
-    );
-    $field = field_create_field($field);
-    $instance = array(
+    ));
+    $field->save();
+    $instance = entity_create('field_instance', array(
       'field_name' => $field_name,
       'entity_type' => 'test_entity',
       'bundle' => 'test_bundle',
-    );
-    field_create_instance($instance);
-
-    $field = field_info_field($instance['field_name']);
-    $instance = field_info_instance($instance['entity_type'], $instance['field_name'], $instance['bundle']);
+    ));
+    $instance->save();
 
     // The storage details are indexed by a storage engine type.
     $this->assertTrue(array_key_exists('drupal_variables', $field['storage_details']), 'The storage type is Drupal variables.');
@@ -345,7 +349,7 @@ function testFieldAttachSaveMissingData() {
   function testFieldAttachSaveMissingDataDefaultValue() {
     // Add a default value function.
     $this->instance['default_value_function'] = 'field_test_default_value';
-    field_update_instance($this->instance);
+    $this->instance->save();
 
     // Verify that fields are populated with default values.
     $entity_type = 'test_entity';
@@ -444,8 +448,8 @@ function testEntityCreateRenameBundle() {
     field_test_create_bundle($new_bundle);
 
     // Add an instance to that bundle.
-    $this->instance['bundle'] = $new_bundle;
-    field_create_instance($this->instance);
+    $this->instance_definition['bundle'] = $new_bundle;
+    entity_create('field_instance', $this->instance_definition)->save();
 
     // Save an entity with data in the field.
     $entity = field_test_create_entity(0, 0, $this->instance['bundle']);
@@ -483,13 +487,13 @@ function testEntityDeleteBundle() {
     field_test_create_bundle($new_bundle);
 
     // Add an instance to that bundle.
-    $this->instance['bundle'] = $new_bundle;
-    field_create_instance($this->instance);
+    $this->instance_definition['bundle'] = $new_bundle;
+    entity_create('field_instance', $this->instance_definition)->save();
 
     // Create a second field for the test bundle
     $field_name = drupal_strtolower($this->randomName() . '_field_name');
     $field = array('field_name' => $field_name, 'type' => 'test_field', 'cardinality' => 1);
-    field_create_field($field);
+    entity_create('field_entity', $field)->save();
     $instance = array(
       'field_name' => $field_name,
       'entity_type' => 'test_entity',
@@ -498,7 +502,7 @@ function testEntityDeleteBundle() {
       'description' => $this->randomName() . '_description',
       'weight' => mt_rand(0, 127),
     );
-    field_create_instance($instance);
+    entity_create('field_instance', $instance)->save();
 
     // Save an entity with data for both fields
     $entity = field_test_create_entity(0, 0, $this->instance['bundle']);
diff --git a/core/modules/field/lib/Drupal/field/Tests/FieldInfoTest.php b/core/modules/field/lib/Drupal/field/Tests/FieldInfoTest.php
index dad0e54..dde8d57 100644
--- a/core/modules/field/lib/Drupal/field/Tests/FieldInfoTest.php
+++ b/core/modules/field/lib/Drupal/field/Tests/FieldInfoTest.php
@@ -2,7 +2,7 @@
 
 /**
  * @file
- * Definition of Drupal\field\Tests\FieldInfoTest.
+ * Contains \Drupal\field\Tests\FieldInfoTest.
  */
 
 namespace Drupal\field\Tests;
@@ -54,11 +54,11 @@ function testFieldInfo() {
 
     // Create a field, verify it shows up.
     $core_fields = field_info_fields();
-    $field = array(
+    $field = entity_create('field_entity', array(
       'field_name' => drupal_strtolower($this->randomName()),
       'type' => 'test_field',
-    );
-    field_create_field($field);
+    ));
+    $field->save();
     $fields = field_info_fields();
     $this->assertEqual(count($fields), count($core_fields) + 1, 'One new field exists');
     $this->assertEqual($fields[$field['field_name']]['field_name'], $field['field_name'], 'info fields contains field name');
@@ -72,7 +72,7 @@ function testFieldInfo() {
     $this->assertEqual($fields[$field['field_name']]['active'], TRUE, 'info fields contains active 1');
 
     // Create an instance, verify that it shows up
-    $instance = array(
+    $instance_definition = array(
       'field_name' => $field['field_name'],
       'entity_type' => 'test_entity',
       'bundle' => 'test_bundle',
@@ -80,14 +80,15 @@ function testFieldInfo() {
       'description' => $this->randomName(),
       'weight' => mt_rand(0, 127),
     );
-    field_create_instance($instance);
+    $instance = entity_create('field_instance', $instance_definition);
+    $instance->save();
 
     $info = entity_get_info('test_entity');
     $instances = field_info_instances('test_entity', $instance['bundle']);
     $this->assertEqual(count($instances), 1, format_string('One instance shows up in info when attached to a bundle on a @label.', array(
       '@label' => $info['label']
     )));
-    $this->assertTrue($instance < $instances[$instance['field_name']], 'Instance appears in info correctly');
+    $this->assertTrue($instance_definition < $instances[$instance['field_name']], 'Instance appears in info correctly');
 
     // Test a valid entity type but an invalid bundle.
     $instances = field_info_instances('test_entity', 'invalid_bundle');
@@ -127,7 +128,8 @@ function testFieldPrepare() {
       'field_name' => 'field',
       'type' => 'test_field',
     );
-    $field = field_create_field($field_definition);
+    $field = entity_create('field_entity', $field_definition);
+    $field->save();
 
     // Simulate a stored field definition missing a field setting (e.g. a
     // third-party module adding a new field setting has been enabled, and
@@ -153,13 +155,14 @@ function testInstancePrepare() {
       'field_name' => 'field',
       'type' => 'test_field',
     );
-    field_create_field($field_definition);
+    entity_create('field_entity', $field_definition)->save();
     $instance_definition = array(
       'field_name' => $field_definition['field_name'],
       'entity_type' => 'test_entity',
       'bundle' => 'test_bundle',
     );
-    $instance = field_create_instance($instance_definition);
+    $instance = entity_create('field_instance', $instance_definition);
+    $instance->save();
 
     // Simulate a stored instance definition missing various settings (e.g. a
     // third-party module adding instance or widget settings has been enabled,
@@ -189,13 +192,13 @@ function testInstanceDisabledEntityType() {
       'field_name' => 'field',
       'type' => 'test_field',
     );
-    field_create_field($field_definition);
+    entity_create('field_entity', $field_definition)->save();
     $instance_definition = array(
       'field_name' => 'field',
       'entity_type' => 'comment',
       'bundle' => 'comment_node_article',
     );
-    field_create_instance($instance_definition);
+    entity_create('field_instance', $instance_definition)->save();
 
     // Disable coment module. This clears field_info cache.
     module_disable(array('comment'));
@@ -224,7 +227,7 @@ function testFieldMap() {
       ),
     );
     foreach ($fields as $field) {
-      field_create_field($field);
+      entity_create('field_entity', $field)->save();
     }
 
     // Create a couple instances.
@@ -251,7 +254,7 @@ function testFieldMap() {
       ),
     );
     foreach ($instances as $instance) {
-      field_create_instance($instance);
+      entity_create('field_instance', $instance)->save();
     }
 
     $expected = array(
@@ -308,11 +311,11 @@ function testFieldInfoCache() {
     // Create a test field and ensure it's in the array returned by
     // field_info_fields().
     $field_name = drupal_strtolower($this->randomName());
-    $field = array(
+    $field = entity_create('field_entity', array(
       'field_name' => $field_name,
       'type' => 'test_field',
-    );
-    field_create_field($field);
+    ));
+    $field->save();
     $fields = field_info_fields();
     $this->assertTrue(isset($fields[$field_name]), 'The test field is initially found in the array returned by field_info_fields().');
 
diff --git a/core/modules/field/lib/Drupal/field/Tests/FieldInstanceCrudTest.php b/core/modules/field/lib/Drupal/field/Tests/FieldInstanceCrudTest.php
index 5f9578a..4e8fff1 100644
--- a/core/modules/field/lib/Drupal/field/Tests/FieldInstanceCrudTest.php
+++ b/core/modules/field/lib/Drupal/field/Tests/FieldInstanceCrudTest.php
@@ -2,18 +2,36 @@
 
 /**
  * @file
- * Definition of Drupal\field\Tests\FieldInstanceCrudTest.
+ * Contains \Drupal\field\Tests\FieldInstanceCrudTest.
  */
 
 namespace Drupal\field\Tests;
 
 use Drupal\field\FieldException;
-use Drupal\field\Plugin\Core\Entity\FieldInstance;
 
 class FieldInstanceCrudTest extends FieldUnitTestBase {
 
+  /**
+   * The field entity.
+   *
+   * @var \Drupal\field\Plugin\Core\Entity\Field
+   */
   protected $field;
 
+  /**
+   * The field entity definition.
+   *
+   * @var array
+   */
+  protected $field_definition;
+
+  /**
+   * The field instance entity definition.
+   *
+   * @var array
+   */
+  protected $instance_definition;
+
   public static function getInfo() {
     return array(
       'name' => 'Field instance CRUD tests',
@@ -25,11 +43,12 @@ public static function getInfo() {
   function setUp() {
     parent::setUp();
 
-    $this->field = array(
+    $this->field_definition = array(
       'field_name' => drupal_strtolower($this->randomName()),
       'type' => 'test_field',
     );
-    field_create_field($this->field);
+    $this->field = entity_create('field_entity', $this->field_definition);
+    $this->field->save();
     $this->instance_definition = array(
       'field_name' => $this->field['field_name'],
       'entity_type' => 'test_entity',
@@ -47,14 +66,15 @@ function setUp() {
    * Test the creation of a field instance.
    */
   function testCreateFieldInstance() {
-    $instance = field_create_instance($this->instance_definition);
+    $instance = entity_create('field_instance', $this->instance_definition);
+    $instance->save();
 
     // Read the configuration. Check against raw configuration data rather than
     // the loaded ConfigEntity, to be sure we check that the defaults are
     // applied on write.
     $config = \Drupal::config('field.instance.' . $instance->id())->get();
 
-    $field_type = field_info_field_types($this->field['type']);
+    $field_type = field_info_field_types($this->field_definition['type']);
 
     // Check that default values are set.
     $this->assertEqual($config['required'], FALSE, 'Required defaults to false.');
@@ -66,7 +86,7 @@ function testCreateFieldInstance() {
 
     // Guarantee that the field/bundle combination is unique.
     try {
-      field_create_instance($this->instance_definition);
+      entity_create('field_instance', $this->instance_definition)->save();
       $this->fail(t('Cannot create two instances with the same field / bundle combination.'));
     }
     catch (FieldException $e) {
@@ -76,7 +96,7 @@ function testCreateFieldInstance() {
     // Check that the specified field exists.
     try {
       $this->instance_definition['field_name'] = $this->randomName();
-      field_create_instance($this->instance_definition);
+      entity_create('field_instance', $this->instance_definition)->save();
       $this->fail(t('Cannot create an instance of a non-existing field.'));
     }
     catch (FieldException $e) {
@@ -84,20 +104,21 @@ function testCreateFieldInstance() {
     }
 
     // Create a field restricted to a specific entity type.
-    $field_restricted = array(
+    $field_restricted_definition = array(
       'field_name' => drupal_strtolower($this->randomName()),
       'type' => 'test_field',
       'entity_types' => array('test_cacheable_entity'),
     );
-    field_create_field($field_restricted);
+    $field_restricted = entity_create('field_entity', $field_restricted_definition);
+    $field_restricted->save();
 
     // Check that an instance can be added to an entity type allowed
     // by the field.
     try {
       $instance = $this->instance_definition;
-      $instance['field_name'] = $field_restricted['field_name'];
+      $instance['field_name'] = $field_restricted_definition['field_name'];
       $instance['entity_type'] = 'test_cacheable_entity';
-      field_create_instance($instance);
+      entity_create('field_instance', $instance)->save();
       $this->pass(t('Can create an instance on an entity type allowed by the field.'));
     }
     catch (FieldException $e) {
@@ -108,8 +129,8 @@ function testCreateFieldInstance() {
     // forbidden by the field.
     try {
       $instance = $this->instance_definition;
-      $instance['field_name'] = $field_restricted['field_name'];
-      field_create_instance($instance);
+      $instance['field_name'] = $field_restricted_definition['field_name'];
+      entity_create('field_instance', $instance)->save();
       $this->fail(t('Cannot create an instance on an entity type forbidden by the field.'));
     }
     catch (FieldException $e) {
@@ -123,7 +144,7 @@ function testCreateFieldInstance() {
    * Test reading back an instance definition.
    */
   function testReadFieldInstance() {
-    field_create_instance($this->instance_definition);
+    entity_create('field_instance', $this->instance_definition)->save();
 
     // Read the instance back.
     $instance = field_read_instance('test_entity', $this->instance_definition['field_name'], $this->instance_definition['bundle']);
@@ -136,7 +157,7 @@ function testReadFieldInstance() {
    * Test the update of a field instance.
    */
   function testUpdateFieldInstance() {
-    field_create_instance($this->instance_definition);
+    entity_create('field_instance', $this->instance_definition)->save();
 
     // Check that basic changes are saved.
     $instance = field_read_instance('test_entity', $this->instance_definition['field_name'], $this->instance_definition['bundle']);
@@ -144,7 +165,7 @@ function testUpdateFieldInstance() {
     $instance['label'] = $this->randomName();
     $instance['description'] = $this->randomName();
     $instance['settings']['test_instance_setting'] = $this->randomName();
-    field_update_instance($instance);
+    $instance->save();
 
     $instance_new = field_read_instance('test_entity', $this->instance_definition['field_name'], $this->instance_definition['bundle']);
     $this->assertEqual($instance['required'], $instance_new['required'], '"required" change is saved');
@@ -164,15 +185,15 @@ function testDeleteFieldInstance() {
 
     // Create two instances for the same field so we can test that only one
     // is deleted.
-    field_create_instance($this->instance_definition);
-    $this->another_instance_definition = $this->instance_definition;
-    $this->another_instance_definition['bundle'] .= '_another_bundle';
-    $instance = field_create_instance($this->another_instance_definition);
+    entity_create('field_instance', $this->instance_definition)->save();
+    $another_instance_definition = $this->instance_definition;
+    $another_instance_definition['bundle'] .= '_another_bundle';
+    entity_create('field_instance', $another_instance_definition)->save();
 
     // Test that the first instance is not deleted, and then delete it.
     $instance = field_read_instance('test_entity', $this->instance_definition['field_name'], $this->instance_definition['bundle'], array('include_deleted' => TRUE));
     $this->assertTrue(!empty($instance) && empty($instance['deleted']), 'A new field instance is not marked for deletion.');
-    field_delete_instance($instance);
+    $instance->delete();
 
     // Make sure the instance is marked as deleted when the instance is
     // specifically loaded.
@@ -184,11 +205,11 @@ function testDeleteFieldInstance() {
     $this->assertTrue(empty($instance), 'A deleted field instance is not loaded by default.');
 
     // Make sure the other field instance is not deleted.
-    $another_instance = field_read_instance('test_entity', $this->another_instance_definition['field_name'], $this->another_instance_definition['bundle']);
+    $another_instance = field_read_instance('test_entity', $another_instance_definition['field_name'], $another_instance_definition['bundle']);
     $this->assertTrue(!empty($another_instance) && empty($another_instance['deleted']), 'A non-deleted field instance is not marked for deletion.');
 
     // Make sure the field is deleted when its last instance is deleted.
-    field_delete_instance($another_instance);
+    $another_instance->delete();
     $deleted_fields = \Drupal::state()->get('field.field.deleted');
     $this->assertTrue(isset($deleted_fields[$another_instance['field_id']]), 'A deleted field is marked for deletion.');
     $field = field_read_field($another_instance['field_name']);
diff --git a/core/modules/field/lib/Drupal/field/Tests/FieldUnitTestBase.php b/core/modules/field/lib/Drupal/field/Tests/FieldUnitTestBase.php
index ed3c151..1199d2c 100644
--- a/core/modules/field/lib/Drupal/field/Tests/FieldUnitTestBase.php
+++ b/core/modules/field/lib/Drupal/field/Tests/FieldUnitTestBase.php
@@ -54,12 +54,13 @@ function createFieldWithInstance($suffix = '') {
     $field = 'field' . $suffix;
     $field_id = 'field_id' . $suffix;
     $instance = 'instance' . $suffix;
+    $instance_definition = 'instance_definition' . $suffix;
 
     $this->$field_name = drupal_strtolower($this->randomName() . '_field_name' . $suffix);
-    $this->$field = array('field_name' => $this->$field_name, 'type' => 'test_field', 'cardinality' => 4);
-    $this->$field = field_create_field($this->$field);
+    $this->$field = entity_create('field_entity', array('field_name' => $this->$field_name, 'type' => 'test_field', 'cardinality' => 4));
+    $this->$field->save();
     $this->$field_id = $this->{$field}['uuid'];
-    $this->$instance = array(
+    $this->$instance_definition = array(
       'field_name' => $this->$field_name,
       'entity_type' => 'test_entity',
       'bundle' => 'test_bundle',
@@ -70,7 +71,8 @@ function createFieldWithInstance($suffix = '') {
         'test_instance_setting' => $this->randomName(),
       ),
     );
-    field_create_instance($this->$instance);
+    $this->$instance = entity_create('field_instance', $this->$instance_definition);
+    $this->$instance->save();
 
     entity_get_form_display('test_entity', 'test_bundle', 'default')
       ->setComponent($this->$field_name, array(
diff --git a/core/modules/field/lib/Drupal/field/Tests/FormTest.php b/core/modules/field/lib/Drupal/field/Tests/FormTest.php
index 6e20523..1947c16 100644
--- a/core/modules/field/lib/Drupal/field/Tests/FormTest.php
+++ b/core/modules/field/lib/Drupal/field/Tests/FormTest.php
@@ -53,8 +53,8 @@ function testFieldFormSingle() {
     $this->field = $this->field_single;
     $this->field_name = $this->field['field_name'];
     $this->instance['field_name'] = $this->field_name;
-    field_create_field($this->field);
-    field_create_instance($this->instance);
+    entity_create('field_entity', $this->field)->save();
+    entity_create('field_instance', $this->instance)->save();
     entity_get_form_display($this->instance['entity_type'], $this->instance['bundle'], 'default')
       ->setComponent($this->field_name)
       ->save();
@@ -122,8 +122,8 @@ function testFieldFormDefaultValue() {
     $this->instance['field_name'] = $this->field_name;
     $default = rand(1, 127);
     $this->instance['default_value'] = array(array('value' => $default));
-    field_create_field($this->field);
-    field_create_instance($this->instance);
+    entity_create('field_entity', $this->field)->save();
+    entity_create('field_instance', $this->instance)->save();
     entity_get_form_display($this->instance['entity_type'], $this->instance['bundle'], 'default')
       ->setComponent($this->field_name)
       ->save();
@@ -149,8 +149,8 @@ function testFieldFormSingleRequired() {
     $this->field_name = $this->field['field_name'];
     $this->instance['field_name'] = $this->field_name;
     $this->instance['required'] = TRUE;
-    field_create_field($this->field);
-    field_create_instance($this->instance);
+    entity_create('field_entity', $this->field)->save();
+    entity_create('field_instance', $this->instance)->save();
     entity_get_form_display($this->instance['entity_type'], $this->instance['bundle'], 'default')
       ->setComponent($this->field_name)
       ->save();
@@ -182,16 +182,16 @@ function testFieldFormSingleRequired() {
 //    $this->field = $this->field_multiple;
 //    $this->field_name = $this->field['field_name'];
 //    $this->instance['field_name'] = $this->field_name;
-//    field_create_field($this->field);
-//    field_create_instance($this->instance);
+//    entity_create('field_entity', $this->field)->save();
+//    entity_create('field_instance', $this->instance)->save();
 //  }
 
   function testFieldFormUnlimited() {
     $this->field = $this->field_unlimited;
     $this->field_name = $this->field['field_name'];
     $this->instance['field_name'] = $this->field_name;
-    field_create_field($this->field);
-    field_create_instance($this->instance);
+    entity_create('field_entity', $this->field)->save();
+    entity_create('field_instance', $this->instance)->save();
     entity_get_form_display($this->instance['entity_type'], $this->instance['bundle'], 'default')
       ->setComponent($this->field_name)
       ->save();
@@ -273,28 +273,28 @@ function testFieldFormMultivalueWithRequiredRadio() {
     $this->field = $this->field_unlimited;
     $this->field_name = $this->field['field_name'];
     $this->instance['field_name'] = $this->field_name;
-    field_create_field($this->field);
-    field_create_instance($this->instance);
+    entity_create('field_entity', $this->field)->save();
+    entity_create('field_instance', $this->instance)->save();
     entity_get_form_display($this->instance['entity_type'], $this->instance['bundle'], 'default')
       ->setComponent($this->field_name)
       ->save();
     $langcode = Language::LANGCODE_NOT_SPECIFIED;
 
     // Add a required radio field.
-    field_create_field(array(
+    entity_create('field_entity', array(
       'field_name' => 'required_radio_test',
       'type' => 'list_text',
       'settings' => array(
         'allowed_values' => array('yes' => 'yes', 'no' => 'no'),
       ),
-    ));
+    ))->save();
     $instance = array(
       'field_name' => 'required_radio_test',
       'entity_type' => 'test_entity',
       'bundle' => 'test_bundle',
       'required' => TRUE,
     );
-    field_create_instance($instance);
+    entity_create('field_instance', $instance)->save();
     entity_get_form_display($instance['entity_type'], $instance['bundle'], 'default')
       ->setComponent($instance['field_name'], array(
         'type' => 'options_buttons',
@@ -320,8 +320,8 @@ function testFieldFormJSAddMore() {
     $this->field = $this->field_unlimited;
     $this->field_name = $this->field['field_name'];
     $this->instance['field_name'] = $this->field_name;
-    field_create_field($this->field);
-    field_create_instance($this->instance);
+    entity_create('field_entity', $this->field)->save();
+    entity_create('field_instance', $this->instance)->save();
     entity_get_form_display($this->instance['entity_type'], $this->instance['bundle'], 'default')
       ->setComponent($this->field_name)
       ->save();
@@ -382,8 +382,8 @@ function testFieldFormMultipleWidget() {
     $this->field = $this->field_multiple;
     $this->field_name = $this->field['field_name'];
     $this->instance['field_name'] = $this->field_name;
-    field_create_field($this->field);
-    field_create_instance($this->instance);
+    entity_create('field_entity', $this->field)->save();
+    entity_create('field_instance', $this->instance)->save();
     entity_get_form_display($this->instance['entity_type'], $this->instance['bundle'], 'default')
       ->setComponent($this->field_name, array(
         'type' => 'test_field_widget_multiple',
@@ -426,8 +426,8 @@ function testFieldFormAccess() {
     $field_name = $field['field_name'];
     $instance = $this->instance;
     $instance['field_name'] = $field_name;
-    field_create_field($field);
-    field_create_instance($instance);
+    entity_create('field_entity', $field)->save();
+    entity_create('field_instance', $instance)->save();
     entity_get_form_display($this->instance['entity_type'], $this->instance['bundle'], 'default')
       ->setComponent($field_name)
       ->save();
@@ -444,8 +444,8 @@ function testFieldFormAccess() {
       'bundle' => 'test_bundle',
       'default_value' => array(0 => array('value' => 99)),
     );
-    field_create_field($field_no_access);
-    field_create_instance($instance_no_access);
+    entity_create('field_entity', $field_no_access)->save();
+    entity_create('field_instance', $instance_no_access)->save();
     entity_get_form_display($instance_no_access['entity_type'], $instance_no_access['bundle'], 'default')
       ->setComponent($field_name_no_access)
       ->save();
@@ -501,17 +501,17 @@ function testFieldFormAccess() {
    */
   function testNestedFieldForm() {
     // Add two instances on the 'test_bundle'
-    field_create_field($this->field_single);
-    field_create_field($this->field_unlimited);
+    entity_create('field_entity', $this->field_single)->save();
+    entity_create('field_entity', $this->field_unlimited)->save();
     $this->instance['field_name'] = 'field_single';
     $this->instance['label'] = 'Single field';
-    field_create_instance($this->instance);
+    entity_create('field_instance', $this->instance)->save();
     entity_get_form_display($this->instance['entity_type'], $this->instance['bundle'], 'default')
       ->setComponent($this->instance['field_name'])
       ->save();
     $this->instance['field_name'] = 'field_unlimited';
     $this->instance['label'] = 'Unlimited field';
-    field_create_instance($this->instance);
+    entity_create('field_instance', $this->instance)->save();
     entity_get_form_display($this->instance['entity_type'], $this->instance['bundle'], 'default')
       ->setComponent($this->instance['field_name'])
       ->save();
@@ -619,8 +619,9 @@ function testFieldFormHiddenWidget() {
     $this->field_name = $this->field['field_name'];
     $this->instance['field_name'] = $this->field_name;
     $this->instance['default_value'] = array(0 => array('value' => 99));
-    field_create_field($this->field);
-    field_create_instance($this->instance);
+    entity_create('field_entity', $this->field)->save();
+    $this->instance = entity_create('field_instance', $this->instance);
+    $this->instance->save();
     entity_get_form_display($this->instance['entity_type'], $this->instance['bundle'], 'default')
       ->setComponent($this->instance['field_name'], array(
         'type' => 'hidden',
@@ -644,7 +645,7 @@ function testFieldFormHiddenWidget() {
     // Update the instance to remove the default value and switch to the
     // default widget.
     $this->instance['default_value'] = NULL;
-    field_update_instance($this->instance);
+    $this->instance->save();
     entity_get_form_display($this->instance['entity_type'], $this->instance['bundle'], 'default')
       ->setComponent($this->instance['field_name'], array(
         'type' => 'test_field_widget',
diff --git a/core/modules/field/lib/Drupal/field/Tests/ShapeItemTest.php b/core/modules/field/lib/Drupal/field/Tests/ShapeItemTest.php
index 4e92d7e..3437924 100644
--- a/core/modules/field/lib/Drupal/field/Tests/ShapeItemTest.php
+++ b/core/modules/field/lib/Drupal/field/Tests/ShapeItemTest.php
@@ -38,13 +38,13 @@ public function setUp() {
       'field_name' => 'field_shape',
       'type' => 'shape',
     );
-    field_create_field($this->field);
+    entity_create('field_entity', $this->field)->save();
     $this->instance = array(
       'entity_type' => 'entity_test',
       'field_name' => 'field_shape',
       'bundle' => 'entity_test',
     );
-    field_create_instance($this->instance);
+    entity_create('field_instance', $this->instance)->save();
   }
 
   /**
diff --git a/core/modules/field/lib/Drupal/field/Tests/TestItemTest.php b/core/modules/field/lib/Drupal/field/Tests/TestItemTest.php
index c8ff8fa..063dca4 100644
--- a/core/modules/field/lib/Drupal/field/Tests/TestItemTest.php
+++ b/core/modules/field/lib/Drupal/field/Tests/TestItemTest.php
@@ -38,13 +38,13 @@ public function setUp() {
       'field_name' => 'field_test',
       'type' => 'test_field',
     );
-    field_create_field($this->field);
+    entity_create('field_entity', $this->field)->save();
     $this->instance = array(
       'entity_type' => 'entity_test',
       'field_name' => 'field_test',
       'bundle' => 'entity_test',
     );
-    field_create_instance($this->instance);
+    entity_create('field_instance', $this->instance)->save();
   }
 
   /**
diff --git a/core/modules/field/lib/Drupal/field/Tests/TranslationTest.php b/core/modules/field/lib/Drupal/field/Tests/TranslationTest.php
index ae52f2e..37787a8 100644
--- a/core/modules/field/lib/Drupal/field/Tests/TranslationTest.php
+++ b/core/modules/field/lib/Drupal/field/Tests/TranslationTest.php
@@ -49,7 +49,7 @@ function setUp() {
       'cardinality' => 4,
       'translatable' => TRUE,
     );
-    field_create_field($this->field_definition);
+    entity_create('field_entity', $this->field_definition)->save();
     $this->field = field_read_field($this->field_name);
 
     $this->instance_definition = array(
@@ -57,7 +57,7 @@ function setUp() {
       'entity_type' => $this->entity_type,
       'bundle' => 'test_bundle',
     );
-    field_create_instance($this->instance_definition);
+    entity_create('field_instance', $this->instance_definition)->save();
     $this->instance = field_read_instance('test_entity', $this->field_name, 'test_bundle');
 
     for ($i = 0; $i < 3; ++$i) {
@@ -95,7 +95,7 @@ function testFieldAvailableLanguages() {
 
     // Test field_available_languages() behavior for untranslatable fields.
     $this->field['translatable'] = FALSE;
-    field_update_field($this->field);
+    $this->field->save();
     $available_langcodes = field_available_languages($this->entity_type, $this->field);
     $this->assertTrue(count($available_langcodes) == 1 && $available_langcodes[0] === Language::LANGCODE_NOT_SPECIFIED, 'For untranslatable fields only Language::LANGCODE_NOT_SPECIFIED is available.');
   }
@@ -251,12 +251,13 @@ function testTranslatableFieldSaveLoad() {
     $field_name_default = drupal_strtolower($this->randomName() . '_field_name');
     $field_definition = $this->field_definition;
     $field_definition['field_name'] = $field_name_default;
-    $field = field_create_field($field_definition);
+    entity_create('field_entity', $field_definition)->save();
 
     $instance_definition = $this->instance_definition;
     $instance_definition['field_name'] = $field_name_default;
     $instance_definition['default_value'] = array(array('value' => rand(1, 127)));
-    $instance = field_create_instance($instance_definition);
+    $instance = entity_create('field_instance', $instance_definition);
+    $instance->save();
 
     $translation_langcodes = array_slice($available_langcodes, 0, 2);
     asort($translation_langcodes);
@@ -310,14 +311,14 @@ function testFieldDisplayLanguage() {
       'cardinality' => 2,
       'translatable' => TRUE,
     );
-    field_create_field($field);
+    entity_create('field_entity', $field)->save();
 
     $instance = array(
       'field_name' => $field['field_name'],
       'entity_type' => $entity_type,
       'bundle' => 'test_bundle',
     );
-    field_create_instance($instance);
+    entity_create('field_instance', $instance)->save();
 
     $entity = field_test_create_entity(1, 1, $this->instance['bundle']);
     $instances = field_info_instances($entity_type, $this->instance['bundle']);
diff --git a/core/modules/field/lib/Drupal/field/Tests/TranslationWebTest.php b/core/modules/field/lib/Drupal/field/Tests/TranslationWebTest.php
index 786f1b4..102c69c 100644
--- a/core/modules/field/lib/Drupal/field/Tests/TranslationWebTest.php
+++ b/core/modules/field/lib/Drupal/field/Tests/TranslationWebTest.php
@@ -42,7 +42,7 @@ function setUp() {
       'cardinality' => 4,
       'translatable' => TRUE,
     );
-    field_create_field($field);
+    entity_create('field_entity', $field)->save();
     $this->field = field_read_field($this->field_name);
 
     $instance = array(
@@ -50,7 +50,7 @@ function setUp() {
       'entity_type' => $this->entity_type,
       'bundle' => 'test_bundle',
     );
-    field_create_instance($instance);
+    entity_create('field_instance', $instance)->save();
     $this->instance = field_read_instance('test_entity', $this->field_name, 'test_bundle');
 
     entity_get_form_display($this->entity_type, 'test_bundle', 'default')
diff --git a/core/modules/field/lib/Drupal/field/Tests/Views/ApiDataTest.php b/core/modules/field/lib/Drupal/field/Tests/Views/ApiDataTest.php
index f187422..386e35d 100644
--- a/core/modules/field/lib/Drupal/field/Tests/Views/ApiDataTest.php
+++ b/core/modules/field/lib/Drupal/field/Tests/Views/ApiDataTest.php
@@ -36,7 +36,7 @@ function setUp() {
       'entity_type' => 'node',
       'bundle' => 'page',
     );
-    field_create_instance($instance);
+    entity_create('field_instance', $instance)->save();
 
     // The second one will be attached to users only.
     $instance = array(
@@ -44,7 +44,7 @@ function setUp() {
       'entity_type' => 'user',
       'bundle' => 'user',
     );
-    field_create_instance($instance);
+    entity_create('field_instance', $instance)->save();
 
     // The third will be attached to both nodes and users.
     $instance = array(
@@ -52,13 +52,13 @@ function setUp() {
       'entity_type' => 'node',
       'bundle' => 'page',
     );
-    field_create_instance($instance);
+    entity_create('field_instance', $instance)->save();
     $instance = array(
       'field_name' => $field_names[2],
       'entity_type' => 'user',
       'bundle' => 'user',
     );
-    field_create_instance($instance);
+    entity_create('field_instance', $instance)->save();
 
     // Now create some example nodes/users for the view result.
     for ($i = 0; $i < 5; $i++) {
diff --git a/core/modules/field/lib/Drupal/field/Tests/Views/FieldTestBase.php b/core/modules/field/lib/Drupal/field/Tests/Views/FieldTestBase.php
index c0f500b..dcc43ae 100644
--- a/core/modules/field/lib/Drupal/field/Tests/Views/FieldTestBase.php
+++ b/core/modules/field/lib/Drupal/field/Tests/Views/FieldTestBase.php
@@ -58,7 +58,8 @@ function setUpFields($amount = 3) {
       $field_names[$i] = 'field_name_' . $i;
       $field = array('field_name' => $field_names[$i], 'type' => 'text');
 
-      $this->fields[$i] = $field = field_create_field($field);
+      $this->fields[$i] = $field = entity_create('field_entity', $field);
+      $field->save();
     }
     return $field_names;
   }
@@ -70,7 +71,8 @@ function setUpInstances($bundle = 'page') {
         'entity_type' => 'node',
         'bundle' => 'page',
       );
-      $this->instances[$key] = field_create_instance($instance);
+      $this->instances[$key] = entity_create('field_instance', $instance);
+      $this->instances[$key]->save();
     }
   }
 
diff --git a/core/modules/field/lib/Drupal/field/Tests/Views/HandlerFieldFieldTest.php b/core/modules/field/lib/Drupal/field/Tests/Views/HandlerFieldFieldTest.php
index b494a5a..4512089 100644
--- a/core/modules/field/lib/Drupal/field/Tests/Views/HandlerFieldFieldTest.php
+++ b/core/modules/field/lib/Drupal/field/Tests/Views/HandlerFieldFieldTest.php
@@ -47,9 +47,11 @@ protected function setUp() {
     $this->setUpFields(3);
 
     // Setup a field with cardinality > 1.
-    $this->fields[3] = $field = field_create_field(array('field_name' => 'field_name_3', 'type' => 'text', 'cardinality' => FIELD_CARDINALITY_UNLIMITED));
+    $this->fields[3] = $field = entity_create('field_entity', array('field_name' => 'field_name_3', 'type' => 'text', 'cardinality' => FIELD_CARDINALITY_UNLIMITED));
+    $field->save();
     // Setup a field that will have no value.
-    $this->fields[4] = $field = field_create_field(array('field_name' => 'field_name_4', 'type' => 'text', 'cardinality' => FIELD_CARDINALITY_UNLIMITED));
+    $this->fields[4] = $field = entity_create('field_entity', array('field_name' => 'field_name_4', 'type' => 'text', 'cardinality' => FIELD_CARDINALITY_UNLIMITED));
+    $field->save();
 
     $this->setUpInstances();
 
diff --git a/core/modules/field/tests/modules/field_test/field_test.module b/core/modules/field/tests/modules/field_test/field_test.module
index c2070f2..7b963be 100644
--- a/core/modules/field/tests/modules/field_test/field_test.module
+++ b/core/modules/field/tests/modules/field_test/field_test.module
@@ -147,7 +147,7 @@ function field_test_field_language_alter(&$display_langcode, $context) {
  *   field_test_memorize();
  *
  *   // call some Field API functions that invoke field_test hooks
- *   $field = field_create_field(...);
+ *   entity_create('field_entity', $field_definition)->save();
  *
  *   // retrieve and reset the memorized hook call data
  *   $mem = field_test_memorize();
diff --git a/core/modules/search/lib/Drupal/search/Tests/SearchMultilingualEntityTest.php b/core/modules/search/lib/Drupal/search/Tests/SearchMultilingualEntityTest.php
index e9526d8..f35b254 100644
--- a/core/modules/search/lib/Drupal/search/Tests/SearchMultilingualEntityTest.php
+++ b/core/modules/search/lib/Drupal/search/Tests/SearchMultilingualEntityTest.php
@@ -49,8 +49,8 @@ function setUp() {
     // Make the body field translatable.
     // The parent class has already created the article and page content types.
     $field = field_info_field('body');
-    $field['translatable'] = TRUE;
-    field_update_field($field);
+    $field->translatable = TRUE;
+    $field->save();
 
     // Create a few page nodes with multilingual body values.
     $default_format = filter_default_format();
diff --git a/core/modules/serialization/lib/Drupal/serialization/Tests/EntityResolverTest.php b/core/modules/serialization/lib/Drupal/serialization/Tests/EntityResolverTest.php
index dfbb7ba..48d0293 100644
--- a/core/modules/serialization/lib/Drupal/serialization/Tests/EntityResolverTest.php
+++ b/core/modules/serialization/lib/Drupal/serialization/Tests/EntityResolverTest.php
@@ -34,22 +34,20 @@ protected function setUp() {
     parent::setUp();
 
     // Create the test field.
-    $field = array(
+    entity_create('field_entity', array(
       'settings' => array(
         'target_type' => 'entity_test_mulrev',
       ),
       'field_name' => 'field_test_entity_reference',
       'type' => 'entity_reference',
-    );
-    field_create_field($field);
+    ))->save();
 
     // Create the test field instance.
-    $instance = array(
+    entity_create('field_instance', array(
       'entity_type' => 'entity_test_mulrev',
       'field_name' => 'field_test_entity_reference',
       'bundle' => 'entity_test_mulrev',
-    );
-    field_create_instance($instance);
+    ))->save();
   }
 
   /**
diff --git a/core/modules/serialization/lib/Drupal/serialization/Tests/NormalizerTestBase.php b/core/modules/serialization/lib/Drupal/serialization/Tests/NormalizerTestBase.php
index 1d9bff6..74fa8d9 100644
--- a/core/modules/serialization/lib/Drupal/serialization/Tests/NormalizerTestBase.php
+++ b/core/modules/serialization/lib/Drupal/serialization/Tests/NormalizerTestBase.php
@@ -26,13 +26,13 @@ protected function setUp() {
     $this->installConfig(array('field'));
 
     // Auto-create a field for testing.
-    field_create_field(array(
+    entity_create('field_entity', array(
       'field_name' => 'field_test_text',
       'type' => 'text',
       'cardinality' => 1,
       'translatable' => FALSE,
-    ));
-    $instance = array(
+    ))->save();
+    entity_create('field_instance', array(
       'entity_type' => 'entity_test_mulrev',
       'field_name' => 'field_test_text',
       'bundle' => 'entity_test_mulrev',
@@ -41,7 +41,7 @@ protected function setUp() {
         'type' => 'text_textfield',
         'weight' => 0,
       ),
-    );
-    field_create_instance($instance);
+    ))->save();
   }
+
 }
diff --git a/core/modules/simpletest/lib/Drupal/simpletest/Tests/DrupalUnitTestBaseTest.php b/core/modules/simpletest/lib/Drupal/simpletest/Tests/DrupalUnitTestBaseTest.php
index b2eed63..4615b39 100644
--- a/core/modules/simpletest/lib/Drupal/simpletest/Tests/DrupalUnitTestBaseTest.php
+++ b/core/modules/simpletest/lib/Drupal/simpletest/Tests/DrupalUnitTestBaseTest.php
@@ -231,17 +231,16 @@ function testEnableModulesFixedList() {
       'bundle' => 'entity_test',
       'mode' => 'default',
     ));
-    $field = array(
+    $field = entity_create('field_entity', array(
       'field_name' => 'test_field',
       'type' => 'test_field'
-    );
-    field_create_field($field);
-    $instance = array(
-      'field_name' => $field['field_name'],
+    ));
+    $field->save();
+    entity_create('field_instance', array(
+      'field_name' => $field->id(),
       'entity_type' => 'entity_test',
       'bundle' => 'entity_test',
-    );
-    field_create_instance($instance);
+    ))->save();
   }
 
   /**
diff --git a/core/modules/system/lib/Drupal/system/Tests/Ajax/MultiFormTest.php b/core/modules/system/lib/Drupal/system/Tests/Ajax/MultiFormTest.php
index d3ba0b7..f15f382 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Ajax/MultiFormTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Ajax/MultiFormTest.php
@@ -34,18 +34,16 @@ function setUp() {
 
     // Create a multi-valued field for 'page' nodes to use for Ajax testing.
     $field_name = 'field_ajax_test';
-    $field = array(
+    entity_create('field_entity', array(
       'field_name' => $field_name,
       'type' => 'text',
       'cardinality' => FIELD_CARDINALITY_UNLIMITED,
-    );
-    field_create_field($field);
-    $instance = array(
+    ))->save();
+    entity_create('field_instance', array(
       'field_name' => $field_name,
       'entity_type' => 'node',
       'bundle' => 'page',
-    );
-    field_create_instance($instance);
+    ))->save();
     entity_get_form_display('node', 'page', 'default')
       ->setComponent($field_name, array('type' => 'text_default'))
       ->save();
diff --git a/core/modules/system/lib/Drupal/system/Tests/Entity/EntityFieldTest.php b/core/modules/system/lib/Drupal/system/Tests/Entity/EntityFieldTest.php
index 93fc552..4d24a51 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Entity/EntityFieldTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Entity/EntityFieldTest.php
@@ -598,8 +598,8 @@ public function testComputedProperties() {
   protected function assertComputedProperties($entity_type) {
     // Make the test text field processed.
     $instance = field_info_instance($entity_type, 'field_test_text', $entity_type);
-    $instance['settings']['text_processing'] = 1;
-    field_update_instance($instance);
+    $instance->settings['text_processing'] = 1;
+    $instance->save();
 
     $entity = $this->createTestEntity($entity_type);
     $entity->field_test_text->value = "The <strong>text</strong> text to filter.";
diff --git a/core/modules/system/lib/Drupal/system/Tests/Entity/EntityQueryAggregateTest.php b/core/modules/system/lib/Drupal/system/Tests/Entity/EntityQueryAggregateTest.php
index 54c6934..faa7090 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Entity/EntityQueryAggregateTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Entity/EntityQueryAggregateTest.php
@@ -60,18 +60,17 @@ public function setUp() {
 
     // Add some fieldapi fields to be used in the test.
     for ($i = 1; $i <= 2; $i++) {
-      $field = array(
-        'field_name' => 'field_test_' . $i,
+      $field_name = 'field_test_' . $i;
+      entity_create('field_entity', array(
+        'field_name' => $field_name,
         'type' => 'number_integer',
         'cardinality' => 2,
-      );
-      field_create_field($field);
-      $instance = array(
-        'field_name' => $field['field_name'],
+      ))->save();
+      entity_create('field_instance', array(
+        'field_name' => $field_name,
         'entity_type' => 'entity_test',
         'bundle' => 'entity_test',
-      );
-      field_create_instance($instance);
+      ))->save();
     }
 
     $entity = $this->entityStorageController->create(array(
diff --git a/core/modules/system/lib/Drupal/system/Tests/Entity/EntityQueryRelationshipTest.php b/core/modules/system/lib/Drupal/system/Tests/Entity/EntityQueryRelationshipTest.php
index f36fca7..7a40d9b 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Entity/EntityQueryRelationshipTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Entity/EntityQueryRelationshipTest.php
@@ -85,14 +85,13 @@ public function setUp() {
       'type' => 'taxonomy_term_reference',
     );
     $field['settings']['allowed_values']['vocabulary'] = $vocabulary->id();
-    field_create_field($field);
+    entity_create('field_entity', $field)->save();
     // Third, create the instance.
-    $instance = array(
+    entity_create('field_instance', array(
       'entity_type' => 'entity_test',
       'field_name' => $this->fieldName,
       'bundle' => 'entity_test',
-    );
-    field_create_instance($instance);
+    ))->save();
     // Create two terms and also two accounts.
     for ($i = 0; $i <= 1; $i++) {
       $term = entity_create('taxonomy_term', array(
diff --git a/core/modules/system/lib/Drupal/system/Tests/Entity/EntityQueryTest.php b/core/modules/system/lib/Drupal/system/Tests/Entity/EntityQueryTest.php
index 8b5b19b..b172572 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Entity/EntityQueryTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Entity/EntityQueryTest.php
@@ -61,13 +61,13 @@ function setUp() {
     $figures = drupal_strtolower($this->randomName());
     $greetings = drupal_strtolower($this->randomName());
     foreach (array($figures => 'shape', $greetings => 'text') as $field_name => $field_type) {
-      $field = array(
+      $fields[] = $field = entity_create('field_enitty', array(
         'field_name' => $field_name,
         'type' => $field_type,
         'cardinality' => 2,
         'translatable' => TRUE,
-      );
-      $fields[] = field_create_field($field);
+      ));
+      $field->save();
     }
     $bundles = array();
     for ($i = 0; $i < 2; $i++) {
@@ -78,12 +78,11 @@ function setUp() {
       } while ($bundles && strtolower($bundles[0]) >= strtolower($bundle));
       entity_test_create_bundle($bundle);
       foreach ($fields as $field) {
-        $instance = array(
-          'field_name' => $field['field_name'],
+        entity_create('field_instance', array(
+          'field_name' => $field->id(),
           'entity_type' => 'entity_test_mulrev',
           'bundle' => $bundle,
-        );
-        field_create_instance($instance);
+        ))->save();
       }
       $bundles[] = $bundle;
     }
@@ -410,12 +409,11 @@ protected function testCount() {
     // can test whether cross entity type fields produce the correct query.
     $field_name = $this->figures;
     $bundle = $this->randomName();
-    $instance = array(
+    entity_create('field_entity', array(
       'field_name' => $field_name,
       'entity_type' => 'entity_test',
       'bundle' => $bundle,
-    );
-    field_create_instance($instance);
+    ))->save();
 
     $entity = entity_create('entity_test', array(
       'id' => 1,
diff --git a/core/modules/system/lib/Drupal/system/Tests/Entity/EntityTranslationFormTest.php b/core/modules/system/lib/Drupal/system/Tests/Entity/EntityTranslationFormTest.php
index 2a6e833..6623d3f 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Entity/EntityTranslationFormTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Entity/EntityTranslationFormTest.php
@@ -105,8 +105,8 @@ function testEntityFormLanguage() {
 
     // Make body translatable.
     $field = field_info_field('body');
-    $field['translatable'] = TRUE;
-    field_update_field($field);
+    $field->translatable = TRUE;
+    $field->save();
     $field = field_info_field('body');
     $this->assertTrue($field['translatable'], 'Field body is translatable.');
 
diff --git a/core/modules/system/lib/Drupal/system/Tests/Entity/EntityTranslationTest.php b/core/modules/system/lib/Drupal/system/Tests/Entity/EntityTranslationTest.php
index 919565c..a235add 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Entity/EntityTranslationTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Entity/EntityTranslationTest.php
@@ -50,23 +50,21 @@ function setUp() {
 
     // Create a translatable test field.
     $this->field_name = drupal_strtolower($this->randomName() . '_field_name');
-    $field = array(
+    entity_create('field_entity', array(
       'field_name' => $this->field_name,
       'type' => 'text',
       'cardinality' => 4,
       'translatable' => TRUE,
-    );
-    field_create_field($field);
+    ))->save();
     $this->field = field_read_field($this->field_name);
 
     // Create instance in all entity variations.
     foreach (entity_test_entity_types() as $entity_type) {
-      $instance = array(
+      entity_create('field_instance', array(
         'field_name' => $this->field_name,
         'entity_type' => $entity_type,
         'bundle' => $entity_type,
-      );
-      field_create_instance($instance);
+      ))->save();
       $this->instance[$entity_type] = field_read_instance($entity_type, $this->field_name, $entity_type);
     }
 
diff --git a/core/modules/system/lib/Drupal/system/Tests/Form/ArbitraryRebuildTest.php b/core/modules/system/lib/Drupal/system/Tests/Form/ArbitraryRebuildTest.php
index f049ac8..ff1bad3 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Form/ArbitraryRebuildTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Form/ArbitraryRebuildTest.php
@@ -33,15 +33,13 @@ function setUp() {
     parent::setUp();
 
     // Auto-create a field for testing.
-    $field = array(
+    entity_create('field_entity', array(
       'field_name' => 'test_multiple',
       'type' => 'text',
       'cardinality' => -1,
       'translatable' => FALSE,
-    );
-    field_create_field($field);
-
-    $instance = array(
+    ))->save();
+    entity_create('field_instance', array(
       'entity_type' => 'user',
       'field_name' => 'test_multiple',
       'bundle' => 'user',
@@ -49,8 +47,7 @@ function setUp() {
       'settings' => array(
         'user_register_form' => TRUE,
       ),
-    );
-    field_create_instance($instance);
+    ))->save();
     entity_get_form_display('user', 'user', 'default')
       ->setComponent('test_multiple', array(
         'type' => 'text_textfield',
diff --git a/core/modules/system/lib/Drupal/system/Tests/Form/RebuildTest.php b/core/modules/system/lib/Drupal/system/Tests/Form/RebuildTest.php
index 8e9f649..c580e88 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Form/RebuildTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Form/RebuildTest.php
@@ -76,13 +76,13 @@ function testPreserveFormActionAfterAJAX() {
       'type' => 'text',
       'cardinality' => FIELD_CARDINALITY_UNLIMITED,
     );
-    field_create_field($field);
+    entity_create('field_entity', $field)->save();
     $instance = array(
       'field_name' => $field_name,
       'entity_type' => 'node',
       'bundle' => 'page',
     );
-    field_create_instance($instance);
+    entity_create('field_instance', $instance)->save();
     entity_get_form_display('node', 'page', 'default')
       ->setComponent($field_name, array('type' => 'text_test'))
       ->save();
diff --git a/core/modules/system/tests/modules/entity_test/entity_test.install b/core/modules/system/tests/modules/entity_test/entity_test.install
index f7b8726..d6f1b34 100644
--- a/core/modules/system/tests/modules/entity_test/entity_test.install
+++ b/core/modules/system/tests/modules/entity_test/entity_test.install
@@ -10,13 +10,12 @@
  */
 function entity_test_install() {
   // Auto-create a field for testing.
-  $field = array(
+  entity_create('field_entity', array(
     'field_name' => 'field_test_text',
     'type' => 'text',
     'cardinality' => 1,
     'translatable' => FALSE,
-  );
-  field_create_field($field);
+  ))->save();
 
   $entity_types = array(
     'entity_test',
@@ -25,13 +24,12 @@ function entity_test_install() {
     'entity_test_mulrev',
   );
   foreach ($entity_types as $entity_type) {
-    $instance = array(
+    entity_create('field_instance', array(
       'entity_type' => $entity_type,
       'field_name' => 'field_test_text',
       'bundle' => $entity_type,
       'label' => 'Test text-field',
-    );
-    field_create_instance($instance);
+    ))->save();
 
     entity_get_form_display($entity_type, $entity_type, 'default')
       ->setComponent('field_test_text', array('type' => 'text_text'))
diff --git a/core/modules/user/lib/Drupal/user/Tests/UserRegistrationTest.php b/core/modules/user/lib/Drupal/user/Tests/UserRegistrationTest.php
index 8da2c2b..a0fe1ff 100644
--- a/core/modules/user/lib/Drupal/user/Tests/UserRegistrationTest.php
+++ b/core/modules/user/lib/Drupal/user/Tests/UserRegistrationTest.php
@@ -195,34 +195,34 @@ function testRegistrationDefaultValues() {
    */
   function testRegistrationWithUserFields() {
     // Create a field, and an instance on 'user' entity type.
-    $field = array(
+    $field = entity_create('field_entity', array(
       'type' => 'test_field',
       'field_name' => 'test_user_field',
       'cardinality' => 1,
-    );
-    field_create_field($field);
-    $instance = array(
+    ));
+    $field->save();
+    $instance = entity_create('field_instance', array(
       'field_name' => 'test_user_field',
       'entity_type' => 'user',
       'label' => 'Some user field',
       'bundle' => 'user',
       'required' => TRUE,
       'settings' => array('user_register_form' => FALSE),
-    );
-    field_create_instance($instance);
+    ));
+    $instance->save();
     entity_get_form_display('user', 'user', 'default')
       ->setComponent('test_user_field', array('type' => 'test_field_widget'))
       ->save();
 
     // Check that the field does not appear on the registration form.
     $this->drupalGet('user/register');
-    $this->assertNoText($instance['label'], 'The field does not appear on user registration form');
+    $this->assertNoText($instance->id(), 'The field does not appear on user registration form');
 
     // Have the field appear on the registration form.
-    $instance['settings']['user_register_form'] = TRUE;
-    field_update_instance($instance);
+    $instance->settings['user_register_form'] = TRUE;
+    $instance->save();
     $this->drupalGet('user/register');
-    $this->assertText($instance['label'], 'The field appears on user registration form');
+    $this->assertText($instance->id(), 'The field appears on user registration form');
 
     // Check that validation errors are correctly reported.
     $edit = array();
@@ -231,11 +231,11 @@ function testRegistrationWithUserFields() {
     // Missing input in required field.
     $edit['test_user_field[und][0][value]'] = '';
     $this->drupalPost(NULL, $edit, t('Create new account'));
-    $this->assertRaw(t('@name field is required.', array('@name' => $instance['label'])), 'Field validation error was correctly reported.');
+    $this->assertRaw(t('@name field is required.', array('@name' => $instance->id()), 'Field validation error was correctly reported.');
     // Invalid input.
     $edit['test_user_field[und][0][value]'] = '-1';
     $this->drupalPost(NULL, $edit, t('Create new account'));
-    $this->assertRaw(t('%name does not accept the value -1.', array('%name' => $instance['label'])), 'Field validation error was correctly reported.');
+    $this->assertRaw(t('%name does not accept the value -1.', array('%name' => $instance->id())), 'Field validation error was correctly reported.');
 
     // Submit with valid data.
     $value = rand(1, 255);
@@ -247,8 +247,8 @@ function testRegistrationWithUserFields() {
     $this->assertEqual($new_user->test_user_field->value, $value, 'The field value was correclty saved.');
 
     // Check that the 'add more' button works.
-    $field['cardinality'] = FIELD_CARDINALITY_UNLIMITED;
-    field_update_field($field);
+    $field->cardinality = FIELD_CARDINALITY_UNLIMITED;
+    $field->save();
     foreach (array('js', 'nojs') as $js) {
       $this->drupalGet('user/register');
       // Add two inputs.
diff --git a/core/modules/user/user.install b/core/modules/user/user.install
index 69d96b6..d445d41 100644
--- a/core/modules/user/user.install
+++ b/core/modules/user/user.install
@@ -317,7 +317,7 @@ function user_install_picture_field() {
       'default_image' => FALSE,
     ),
   );
-  $field = field_create_field($field);
+  entity_create('field_entity', $field)->save();
 
   $instance = array(
     'field_name' => 'user_picture',
@@ -337,7 +337,7 @@ function user_install_picture_field() {
       'default_image' => 0,
     ),
   );
-  field_create_instance($instance);
+  entity_create('field_instance', $instance)->save();
 
   // Assign form display settings for the 'default' view mode.
   entity_get_form_display('user', 'user', 'default')
diff --git a/core/modules/views/lib/Drupal/views/Tests/DefaultViewsTest.php b/core/modules/views/lib/Drupal/views/Tests/DefaultViewsTest.php
index d5b51d8..acc24e6 100644
--- a/core/modules/views/lib/Drupal/views/Tests/DefaultViewsTest.php
+++ b/core/modules/views/lib/Drupal/views/Tests/DefaultViewsTest.php
@@ -61,7 +61,7 @@ protected function setUp() {
 
     // Setup a field and instance.
     $this->field_name = drupal_strtolower($this->randomName());
-    $this->field = array(
+    entity_create('field_entity', array(
       'field_name' => $this->field_name,
       'type' => 'taxonomy_term_reference',
       'settings' => array(
@@ -72,14 +72,12 @@ protected function setUp() {
           ),
         ),
       )
-    );
-    field_create_field($this->field);
-    $this->instance = array(
+    ))->save();
+    entity_create('field_instance', array(
       'field_name' => $this->field_name,
       'entity_type' => 'node',
       'bundle' => 'page',
-    );
-    field_create_instance($this->instance);
+    ))->save();
 
     // Create a time in the past for the archive.
     $time = time() - 3600;
diff --git a/core/modules/views/lib/Drupal/views/Tests/Wizard/TaggedWithTest.php b/core/modules/views/lib/Drupal/views/Tests/Wizard/TaggedWithTest.php
index bb52895..2f870d8 100644
--- a/core/modules/views/lib/Drupal/views/Tests/Wizard/TaggedWithTest.php
+++ b/core/modules/views/lib/Drupal/views/Tests/Wizard/TaggedWithTest.php
@@ -55,7 +55,7 @@ function setUp() {
     $this->tag_vocabulary->save();
 
     // Create the tag field itself.
-    $this->tag_field = array(
+    $this->tag_field = entity_create('field_entity', array(
       'field_name' => 'field_views_testing_tags',
       'type' => 'taxonomy_term_reference',
       'cardinality' => FIELD_CARDINALITY_UNLIMITED,
@@ -67,8 +67,8 @@ function setUp() {
           ),
         ),
       ),
-    );
-    field_create_field($this->tag_field);
+    ));
+    $this->tag_field->save();
 
     // Create an instance of the tag field on one of the content types, and
     // configure it to display an autocomplete widget.
@@ -77,7 +77,7 @@ function setUp() {
       'entity_type' => 'node',
       'bundle' => $this->node_type_with_tags->type,
     );
-    field_create_instance($this->tag_instance);
+    entity_create('field_instance', $this->tag_instance)->save();
 
     entity_get_form_display('node', $this->node_type_with_tags->type, 'default')
       ->setComponent('field_views_testing_tags', array(
@@ -108,7 +108,7 @@ function testTaggedWith() {
     $node_add_path = 'node/add/' . $this->node_type_with_tags->type;
 
     // Create three nodes, with different tags.
-    $tag_field = $this->tag_field['field_name'] . '[' . Language::LANGCODE_NOT_SPECIFIED . ']';
+    $tag_field = $this->tag_field->id() . '[' . Language::LANGCODE_NOT_SPECIFIED . ']';
     $edit = array();
     $edit['title'] = $node_tag1_title = $this->randomName();
     $edit[$tag_field] = 'tag1';
@@ -189,7 +189,7 @@ function testTaggedWithByNodeType() {
     // "tagged with" form element should not appear for it too.
     $instance = $this->tag_instance;
     $instance['bundle'] = $this->node_type_without_tags->type;
-    field_create_instance($instance);
+    entity_create('field_instance', $instance)->save();
     entity_get_form_display('node', $this->node_type_without_tags->type, 'default')
       ->setComponent('field_views_testing_tags', array(
         'type' => 'taxonomy_autocomplete',