diff --git a/core/lib/Drupal/Core/Entity/ContentEntityBase.php b/core/lib/Drupal/Core/Entity/ContentEntityBase.php
index 3effe8b3c2..5b821c8de0 100644
--- a/core/lib/Drupal/Core/Entity/ContentEntityBase.php
+++ b/core/lib/Drupal/Core/Entity/ContentEntityBase.php
@@ -331,6 +331,16 @@ public function isDefaultRevision($new_value = NULL) {
     return $this->isNew() || $return;
   }
 
+  /**
+   * {@inheritdoc}
+   */
+  public function wasDefaultRevision() {
+    if (!$this->getEntityType()->isRevisionable()) {
+      throw new \LogicException("Entity type {$this->getEntityTypeId()} does not support revisions.");
+    }
+    return (bool) $this->get('default_revision')->value;
+  }
+
   /**
    * {@inheritdoc}
    */
@@ -1269,23 +1279,34 @@ protected function getEntityKey($key) {
    */
   public static function baseFieldDefinitions(EntityTypeInterface $entity_type) {
     $fields = [];
+
     if ($entity_type->hasKey('id')) {
       $fields[$entity_type->getKey('id')] = BaseFieldDefinition::create('integer')
         ->setLabel(new TranslatableMarkup('ID'))
         ->setReadOnly(TRUE)
         ->setSetting('unsigned', TRUE);
     }
+
     if ($entity_type->hasKey('uuid')) {
       $fields[$entity_type->getKey('uuid')] = BaseFieldDefinition::create('uuid')
         ->setLabel(new TranslatableMarkup('UUID'))
         ->setReadOnly(TRUE);
     }
-    if ($entity_type->hasKey('revision')) {
+
+    if ($entity_type->isRevisionable()) {
       $fields[$entity_type->getKey('revision')] = BaseFieldDefinition::create('integer')
         ->setLabel(new TranslatableMarkup('Revision ID'))
         ->setReadOnly(TRUE)
         ->setSetting('unsigned', TRUE);
+
+      $fields['default_revision'] = BaseFieldDefinition::create('boolean')
+        ->setLabel(new TranslatableMarkup('Default revision'))
+        ->setDescription(new TranslatableMarkup('A flag indicating whether this was a default revision when it was saved.'))
+        ->setTranslatable(FALSE)
+        ->setRevisionable(TRUE)
+        ->setRequired(TRUE);
     }
+
     if ($entity_type->hasKey('langcode')) {
       $fields[$entity_type->getKey('langcode')] = BaseFieldDefinition::create('language')
         ->setLabel(new TranslatableMarkup('Language'))
@@ -1303,6 +1324,7 @@ public static function baseFieldDefinitions(EntityTypeInterface $entity_type) {
         $fields[$entity_type->getKey('langcode')]->setTranslatable(TRUE);
       }
     }
+
     if ($entity_type->hasKey('bundle')) {
       if ($bundle_entity_type_id = $entity_type->getBundleEntityType()) {
         $fields[$entity_type->getKey('bundle')] = BaseFieldDefinition::create('entity_reference')
diff --git a/core/lib/Drupal/Core/Entity/ContentEntityInterface.php b/core/lib/Drupal/Core/Entity/ContentEntityInterface.php
index 3053d23694..e85a299312 100644
--- a/core/lib/Drupal/Core/Entity/ContentEntityInterface.php
+++ b/core/lib/Drupal/Core/Entity/ContentEntityInterface.php
@@ -106,4 +106,16 @@ public function getLoadedRevisionId();
    */
   public function updateLoadedRevisionId();
 
+  /**
+   * Checks whether the entity object was a default revision when it was saved.
+   *
+   * @return bool
+   *   TRUE if the entity object was a revision, FALSE otherwise.
+   *
+   * @throws \LogicException
+   *   If the entity type is not revisionable or the default revision data is
+   *   missing.
+   */
+  public function wasDefaultRevision();
+
 }
diff --git a/core/lib/Drupal/Core/Entity/ContentEntityStorageBase.php b/core/lib/Drupal/Core/Entity/ContentEntityStorageBase.php
index a3bb20508f..8803d36802 100644
--- a/core/lib/Drupal/Core/Entity/ContentEntityStorageBase.php
+++ b/core/lib/Drupal/Core/Entity/ContentEntityStorageBase.php
@@ -334,6 +334,9 @@ protected function doSave($id, EntityInterface $entity) {
     }
 
     $this->populateAffectedRevisionTranslations($entity);
+    if ($this->entityType->isRevisionable()) {
+      $entity->set('default_revision', $entity->isDefaultRevision());
+    }
     $this->doSaveFieldItems($entity);
 
     return $return;
diff --git a/core/lib/Drupal/Core/Entity/EntityFieldManager.php b/core/lib/Drupal/Core/Entity/EntityFieldManager.php
index 63c35e9743..040a34c681 100644
--- a/core/lib/Drupal/Core/Entity/EntityFieldManager.php
+++ b/core/lib/Drupal/Core/Entity/EntityFieldManager.php
@@ -220,7 +220,8 @@ protected function buildBaseFieldDefinitions($entity_type_id) {
       }
     }
 
-    // Make sure that revisionable entity types are correctly defined.
+    // Make sure that revisionable and translatable entity types are correctly
+    // defined.
     if ($entity_type->isRevisionable() && $entity_type->isTranslatable()) {
       // The 'revision_translation_affected' field should always be defined.
       // This field has been added unconditionally in Drupal 8.4.0 and it is
diff --git a/core/lib/Drupal/Core/Entity/Sql/SqlContentEntityStorageSchemaConverter.php b/core/lib/Drupal/Core/Entity/Sql/SqlContentEntityStorageSchemaConverter.php
index 60712eeb21..fb497523bd 100644
--- a/core/lib/Drupal/Core/Entity/Sql/SqlContentEntityStorageSchemaConverter.php
+++ b/core/lib/Drupal/Core/Entity/Sql/SqlContentEntityStorageSchemaConverter.php
@@ -293,6 +293,10 @@ protected function copyData(array &$sandbox) {
         // returned was always TRUE.
         $entity->set($revision_translation_affected_key, TRUE);
 
+        // We cannot know what type the revision was so we assume the core
+        // default behavior of always creating a default revision.
+        $entity->set('default_revision', TRUE);
+
         // Treat the entity as new in order to make the storage do an INSERT
         // rather than an UPDATE.
         $entity->enforceIsNew(TRUE);
@@ -380,6 +384,19 @@ protected function updateFieldStorageDefinitionsToRevisionable(ContentEntityType
     }
     $updated_storage_definitions[$entity_type->getKey('revision')] = $revision_field;
 
+    $revision_type_field = BaseFieldDefinition::create('boolean')
+      ->setName('default_revision')
+      ->setLabel(new TranslatableMarkup('Default revision'))
+      ->setDescription(new TranslatableMarkup('A flag indicating whether this was a default revision when it was saved.'))
+      ->setTranslatable(FALSE)
+      ->setRevisionable(TRUE)
+      ->setRequired(TRUE);
+
+    if ($update_cached_definitions) {
+      $this->entityDefinitionUpdateManager->installFieldStorageDefinition($revision_type_field->getName(), $entity_type->id(), $entity_type->getProvider(), $revision_type_field);
+    }
+    $updated_storage_definitions[$revision_type_field->getName()] = $revision_type_field;
+
     // Add the 'revision_translation_affected' field if needed.
     if ($entity_type->isTranslatable()) {
       $revision_translation_affected_field = BaseFieldDefinition::create('boolean')
diff --git a/core/modules/rest/tests/src/Functional/EntityResource/BlockContent/BlockContentResourceTestBase.php b/core/modules/rest/tests/src/Functional/EntityResource/BlockContent/BlockContentResourceTestBase.php
index 5d7329feb9..c652a2c4be 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/BlockContent/BlockContentResourceTestBase.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/BlockContent/BlockContentResourceTestBase.php
@@ -121,6 +121,11 @@ protected function getExpectedNormalizedEntity() {
           'value' => TRUE,
         ],
       ],
+      'default_revision' => [
+        [
+          'value' => TRUE,
+        ],
+      ],
       'default_langcode' => [
         [
           'value' => TRUE,
diff --git a/core/modules/rest/tests/src/Functional/EntityResource/Media/MediaResourceTestBase.php b/core/modules/rest/tests/src/Functional/EntityResource/Media/MediaResourceTestBase.php
index 1875d004a4..b84c96632e 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/Media/MediaResourceTestBase.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/Media/MediaResourceTestBase.php
@@ -212,6 +212,11 @@ protected function getExpectedNormalizedEntity() {
           'value' => TRUE,
         ],
       ],
+      'default_revision' => [
+        [
+          'value' => TRUE,
+        ],
+      ],
     ];
   }
 
diff --git a/core/modules/rest/tests/src/Functional/EntityResource/Node/NodeResourceTestBase.php b/core/modules/rest/tests/src/Functional/EntityResource/Node/NodeResourceTestBase.php
index 492ff642e4..fa972eaa6a 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/Node/NodeResourceTestBase.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/Node/NodeResourceTestBase.php
@@ -152,6 +152,11 @@ protected function getExpectedNormalizedEntity() {
           'value' => TRUE,
         ],
       ],
+      'default_revision' => [
+        [
+          'value' => TRUE,
+        ],
+      ],
       'default_langcode' => [
         [
           'value' => TRUE,
diff --git a/core/modules/serialization/tests/src/Kernel/EntitySerializationTest.php b/core/modules/serialization/tests/src/Kernel/EntitySerializationTest.php
index 5b71b93b7a..88039ba799 100644
--- a/core/modules/serialization/tests/src/Kernel/EntitySerializationTest.php
+++ b/core/modules/serialization/tests/src/Kernel/EntitySerializationTest.php
@@ -129,6 +129,9 @@ public function testNormalize() {
       'revision_translation_affected' => [
         ['value' => TRUE],
       ],
+      'default_revision' => [
+        ['value' => TRUE],
+      ],
       'non_rev_field' => [],
       'field_test_text' => [
         [
@@ -201,6 +204,7 @@ public function testSerialize() {
       'revision_id' => '<revision_id><value>' . $this->entity->getRevisionId() . '</value></revision_id>',
       'default_langcode' => '<default_langcode><value>1</value></default_langcode>',
       'revision_translation_affected' => '<revision_translation_affected><value>1</value></revision_translation_affected>',
+      'default_revision' => '<default_revision><value>1</value></default_revision>',
       'non_rev_field' => '<non_rev_field/>',
       'field_test_text' => '<field_test_text><value>' . $this->values['field_test_text']['value'] . '</value><format>' . $this->values['field_test_text']['format'] . '</format></field_test_text>',
     ];
diff --git a/core/modules/system/system.install b/core/modules/system/system.install
index ef6f124f51..2f59ad4255 100644
--- a/core/modules/system/system.install
+++ b/core/modules/system/system.install
@@ -2056,3 +2056,37 @@ function system_update_8403() {
     }
   }
 }
+
+/**
+ * Add the 'revision_type' field to all entity types.
+ */
+function system_update_8501() {
+  $definition_update_manager = \Drupal::entityDefinitionUpdateManager();
+
+  // Get a list of revisionable entity types.
+  /** @var \Drupal\Core\Entity\ContentEntityTypeInterface[] $definitions */
+  $definitions = array_filter(\Drupal::entityTypeManager()->getDefinitions(), function (EntityTypeInterface $entity_type) use ($definition_update_manager) {
+    if ($entity_type = $definition_update_manager->getEntityType($entity_type->id())) {
+      return $entity_type->isRevisionable();
+    }
+    return FALSE;
+  });
+
+  foreach ($definitions as $entity_type_id => $entity_type) {
+    $field_name = 'default_revision';
+
+    // Install the 'default_revision' field if needed.
+    if (!$definition_update_manager->getFieldStorageDefinition($field_name, $entity_type_id)) {
+      $storage_definition = BaseFieldDefinition::create('boolean')
+        ->setLabel(t('Default revision'))
+        ->setDescription(t('A flag indicating whether this was a default revision when it was saved.'))
+        ->setTranslatable(FALSE)
+        ->setRevisionable(TRUE)
+        ->setRequired(TRUE)
+        ->setInitialValue(TRUE);
+
+      $definition_update_manager
+        ->installFieldStorageDefinition($field_name, $entity_type_id, $entity_type_id, $storage_definition);
+    }
+  }
+}