diff --git a/core/lib/Drupal/Core/Entity/ContentEntityBase.php b/core/lib/Drupal/Core/Entity/ContentEntityBase.php
index 7c0a458..7c0c711 100644
--- a/core/lib/Drupal/Core/Entity/ContentEntityBase.php
+++ b/core/lib/Drupal/Core/Entity/ContentEntityBase.php
@@ -163,6 +163,13 @@
   protected $validationRequired = FALSE;
 
   /**
+   * The original revision id before the new revision was set.
+   *
+   * @var int
+   */
+  protected $originalRevisionId;
+
+  /**
    * {@inheritdoc}
    */
   public function __construct(array $values, $entity_type, $bundle = FALSE, $translations = array()) {
@@ -266,6 +273,7 @@ public function setNewRevision($value = TRUE) {
     if ($value && !$this->newRevision) {
       // When saving a new revision, set any existing revision ID to NULL so as
       // to ensure that a new revision will actually be created.
+      $this->originalRevisionId = $this->getRevisionId();
       $this->set($this->getEntityType()->getKey('revision'), NULL);
 
       // Make sure that the flag tracking which translations are affected by the
@@ -284,6 +292,29 @@ public function setNewRevision($value = TRUE) {
   /**
    * {@inheritdoc}
    */
+  public function getOriginalRevisionId() {
+    $revison_id = $this->originalRevisionId;
+    if (!$revison_id) {
+      $revison_id = $this->getRevisionId();
+    }
+    return $revison_id;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function loadUnchangedRevision() {
+    if ($this->getOriginalRevisionId()) {
+      $storage = $this->entityTypeManager()
+        ->getStorage($this->entityTypeId);
+      $storage->resetCache([$this->id()]);
+      return $storage->loadRevision($this->getOriginalRevisionId());
+    }
+  }
+
+  /**
+   * {@inheritdoc}
+   */
   public function isNewRevision() {
     return $this->newRevision || ($this->getEntityType()->hasKey('revision') && !$this->getRevisionId());
   }
diff --git a/core/lib/Drupal/Core/Entity/RevisionableInterface.php b/core/lib/Drupal/Core/Entity/RevisionableInterface.php
index 14690e3..bb56770 100644
--- a/core/lib/Drupal/Core/Entity/RevisionableInterface.php
+++ b/core/lib/Drupal/Core/Entity/RevisionableInterface.php
@@ -61,4 +61,22 @@ public function isDefaultRevision($new_value = NULL);
    */
   public function preSaveRevision(EntityStorageInterface $storage, \stdClass $record);
 
+  /**
+   * Gets the revision identifier of the original entity revision.
+   *
+   * @return
+   *   The revision identifier of the original entity revision, or NULL if no
+   *   revision identifier.
+   */
+  public function getOriginalRevisionId();
+
+  /**
+   * Loads the unchanged revision entity object.
+   *
+   * @return
+   *   The entity object for the unchanged revision, or NULL if no unchanged
+   *   revision.
+   */
+  public function loadUnchangedRevision();
+
 }
diff --git a/core/tests/Drupal/KernelTests/Core/Entity/EntityOriginalRevisionTest.php b/core/tests/Drupal/KernelTests/Core/Entity/EntityOriginalRevisionTest.php
new file mode 100644
index 0000000..68d8d75
--- /dev/null
+++ b/core/tests/Drupal/KernelTests/Core/Entity/EntityOriginalRevisionTest.php
@@ -0,0 +1,45 @@
+<?php
+
+namespace Drupal\KernelTests\Core\Entity;
+
+use Drupal\entity_test\Entity\EntityTestMulRev;
+
+/**
+ * Tests the original revision of an entity.
+ *
+ * @group entity
+ */
+class EntityOriginalRevisionTest extends EntityKernelTestBase {
+
+  /**
+   * Modules to enable.
+   *
+   * @var array
+   */
+  public static $modules = ['system', 'entity_test'];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp() {
+    parent::setUp();
+
+    $this->installEntitySchema('entity_test_mulrev');
+
+  }
+
+  public function testPreviousProperty() {
+    $entity = EntityTestMulRev::create();
+    $entity->save();
+
+    $loaded = EntityTestMulRev::load($entity->id());
+    $loaded->setNewRevision(TRUE);
+    $loaded->save();
+
+    $this->assertEquals($entity->getRevisionId(), $loaded->getOriginalRevisionId());
+    $this->assertNotEquals($loaded->getRevisionId(), $loaded->getOriginalRevisionId());
+
+    $this->assertEquals($entity->getRevisionId(), $loaded->loadUnchangedRevision()->getRevisionId());
+    $this->assertNotEquals($loaded->getRevisionId(), $loaded->loadUnchangedRevision()->getRevisionId());
+  }
+}
diff --git a/core/tests/Drupal/Tests/Core/Entity/ContentEntityBaseUnitTest.php b/core/tests/Drupal/Tests/Core/Entity/ContentEntityBaseUnitTest.php
index cb73533..bc5965b 100644
--- a/core/tests/Drupal/Tests/Core/Entity/ContentEntityBaseUnitTest.php
+++ b/core/tests/Drupal/Tests/Core/Entity/ContentEntityBaseUnitTest.php
@@ -215,7 +215,7 @@ public function testIsNewRevision() {
       ->method('hasKey')
       ->with('revision')
       ->will($this->returnValue(TRUE));
-    $this->entityType->expects($this->at(5))
+    $this->entityType->expects($this->at(6))
       ->method('getKey')
       ->with('revision')
       ->will($this->returnValue('revision_id'));