diff --git a/src/wp-includes/revision.php b/src/wp-includes/revision.php
index 11f2bba9d97ff..8c49c6e98dc52 100644
--- a/src/wp-includes/revision.php
+++ b/src/wp-includes/revision.php
@@ -100,20 +100,19 @@ function _wp_post_revision_data( $post = array(), $autosave = false ) {
  *
  * @since 6.4.0
  *
- * @param int     $post_id The post id that was inserted.
- * @param WP_Post $post    The post object that was inserted.
+ * @param int     $post_id The post ID that was inserted or updated.
+ * @param WP_Post $post    The post object that was inserted or updated.
  * @param bool    $update  Whether this insert is updating an existing post.
  */
 function wp_save_post_revision_on_insert( $post_id, $post, $update ) {
-	if ( ! $update ) {
-		return;
-	}
-
 	if ( ! has_action( 'post_updated', 'wp_save_post_revision' ) ) {
 		return;
 	}
 
-	wp_save_post_revision( $post_id );
+	wp_save_post_revision(
+		$post_id,
+		! $update && 0 === get_current_user_id() ? $post->post_author : null
+	);
 }
 
 /**
@@ -123,11 +122,13 @@ function wp_save_post_revision_on_insert( $post_id, $post, $update ) {
  * and the most recent revision always matches the current post.
  *
  * @since 2.6.0
+ * @since 7.1.0 The `$revision_author` parameter was added.
  *
- * @param int $post_id The ID of the post to save as a revision.
+ * @param int      $post_id         The ID of the post to save as a revision.
+ * @param int|null $revision_author Optional. The revision author ID. Default null.
  * @return int|WP_Error|null Null or 0 if error, new revision ID, if success.
  */
-function wp_save_post_revision( $post_id ) {
+function wp_save_post_revision( $post_id, $revision_author = null ) {
 	if ( defined( 'DOING_AUTOSAVE' ) && DOING_AUTOSAVE ) {
 		return null;
 	}
@@ -214,7 +215,7 @@ function wp_save_post_revision( $post_id ) {
 		}
 	}
 
-	$return = _wp_put_post_revision( $post );
+	$return = _wp_put_post_revision( $post, false, $revision_author );
 
 	/*
 	 * If a limit for the number of revisions to keep has been set,
@@ -344,14 +345,16 @@ function wp_is_post_autosave( $post ) {
  * Inserts post data into the posts table as a post revision.
  *
  * @since 2.6.0
+ * @since 7.1.0 The `$post_author` parameter was added.
  * @access private
  *
- * @param int|WP_Post|array|null $post     Post ID, post object OR post array.
- * @param bool                   $autosave Optional. Whether the revision is an autosave or not.
- *                                         Default false.
+ * @param int|WP_Post|array|null $post        Post ID, post object OR post array.
+ * @param bool                   $autosave    Optional. Whether the revision is an autosave or not.
+ *                                            Default false.
+ * @param int|null               $post_author Optional. The revision author ID. Default null.
  * @return int|WP_Error WP_Error or 0 if error, new revision ID if success.
  */
-function _wp_put_post_revision( $post = null, $autosave = false ) {
+function _wp_put_post_revision( $post = null, $autosave = false, $post_author = null ) {
 	if ( is_object( $post ) ) {
 		$post = get_object_vars( $post );
 	} elseif ( ! is_array( $post ) ) {
@@ -367,6 +370,11 @@ function _wp_put_post_revision( $post = null, $autosave = false ) {
 	}
 
 	$post = _wp_post_revision_data( $post, $autosave );
+
+	if ( null !== $post_author ) {
+		$post['post_author'] = absint( $post_author );
+	}
+
 	$post = wp_slash( $post ); // Since data is from DB.
 
 	$revision_id = wp_insert_post( $post, true );
diff --git a/src/wp-includes/theme.php b/src/wp-includes/theme.php
index 07869ae61d0ff..222af49a68161 100644
--- a/src/wp-includes/theme.php
+++ b/src/wp-includes/theme.php
@@ -2141,16 +2141,8 @@ function wp_update_custom_css_post( $css, $args = array() ) {
 	} else {
 		$r = wp_insert_post( wp_slash( $post_data ), true );
 
-		if ( ! is_wp_error( $r ) ) {
-			if ( get_stylesheet() === $args['stylesheet'] ) {
-				set_theme_mod( 'custom_css_post_id', $r );
-			}
-
-			// Trigger creation of a revision. This should be removed once #30854 is resolved.
-			$revisions = wp_get_latest_revision_id_and_total_count( $r );
-			if ( ! is_wp_error( $revisions ) && 0 === $revisions['count'] ) {
-				wp_save_post_revision( $r );
-			}
+		if ( ! is_wp_error( $r ) && get_stylesheet() === $args['stylesheet'] ) {
+			set_theme_mod( 'custom_css_post_id', $r );
 		}
 	}
 
diff --git a/tests/phpunit/tests/post/metaRevisions.php b/tests/phpunit/tests/post/metaRevisions.php
index a95cc3a260a26..e6a881cd9ff6a 100644
--- a/tests/phpunit/tests/post/metaRevisions.php
+++ b/tests/phpunit/tests/post/metaRevisions.php
@@ -39,7 +39,7 @@ public function test_revisions_stores_meta_values_with_slashes( $passed, $expect
 		// Set up a new post.
 		$post_id = $this->factory->post->create();
 
-		// And update to store an initial revision.
+		// And update to store another revision.
 		wp_update_post(
 			array(
 				'post_content' => 'some initial content',
@@ -121,7 +121,7 @@ public function test_revisions_stores_meta_values() {
 		$post_id          = $this->factory->post->create();
 		$original_post_id = $post_id;
 
-		// And update to store an initial revision.
+		// And update to store another revision.
 		wp_update_post(
 			array(
 				'post_content' => 'some initial content',
@@ -129,9 +129,9 @@ public function test_revisions_stores_meta_values() {
 			)
 		);
 
-		// One revision so far.
+		// Two revisions so far, including the initial revision.
 		$revisions = wp_get_post_revisions( $post_id );
-		$this->assertCount( 1, $revisions );
+		$this->assertCount( 2, $revisions );
 
 		/*
 		 * First set up a meta value.
@@ -149,7 +149,7 @@ public function test_revisions_stores_meta_values() {
 		);
 
 		$revisions = wp_get_post_revisions( $post_id );
-		$this->assertCount( 2, $revisions );
+		$this->assertCount( 3, $revisions );
 
 		// Next, store some updated meta values for the same key.
 		update_post_meta( $post_id, 'meta_revision_test', 'update1' );
@@ -163,7 +163,7 @@ public function test_revisions_stores_meta_values() {
 		);
 
 		$revisions = wp_get_post_revisions( $post_id );
-		$this->assertCount( 3, $revisions );
+		$this->assertCount( 4, $revisions );
 
 		/*
 		 * Now restore the original revision.
@@ -181,7 +181,7 @@ public function test_revisions_stores_meta_values() {
 
 		wp_update_post( array( 'ID' => $post_id ) );
 		$revisions = wp_get_post_revisions( $post_id );
-		$this->assertCount( 4, $revisions );
+		$this->assertCount( 5, $revisions );
 
 		/*
 		 * Check the meta values to verify they are NOT revisioned - they are not revisioned by default.
@@ -208,7 +208,7 @@ public function test_revisions_stores_meta_values() {
 		);
 
 		$revisions = array_values( wp_get_post_revisions( $post_id ) );
-		$this->assertCount( 5, $revisions );
+		$this->assertCount( 6, $revisions );
 		$this->assertSame( 'update2', get_post_meta( $revisions[0]->ID, 'meta_revision_test', true ) );
 
 		// Store custom meta values, which should now be revisioned.
@@ -228,7 +228,7 @@ public function test_revisions_stores_meta_values() {
 
 		// This revision contains the existing post meta ('update3').
 		$revisions = wp_get_post_revisions( $post_id );
-		$this->assertCount( 6, $revisions );
+		$this->assertCount( 7, $revisions );
 
 		// Verify that previous post meta is set.
 		$this->assertSame( 'update3', get_post_meta( $post_id, 'meta_revision_test', true ) );
diff --git a/tests/phpunit/tests/post/revisions.php b/tests/phpunit/tests/post/revisions.php
index 5b6e70b4605bf..86ec7520b4242 100644
--- a/tests/phpunit/tests/post/revisions.php
+++ b/tests/phpunit/tests/post/revisions.php
@@ -227,7 +227,7 @@ public function test_revision_view_caps_post() {
 		);
 
 		$revisions = wp_get_post_revisions( $post_id );
-		$this->assertCount( 1, $revisions );
+		$this->assertCount( 2, $revisions );
 		$this->assertTrue( user_can( self::$editor_user_id, 'read_post', $post_id ) );
 
 		$this->assertNotEmpty( $revisions );
@@ -262,7 +262,7 @@ public function test_revision_restore_caps_post() {
 		);
 
 		$revisions = wp_get_post_revisions( $post_id );
-		$this->assertCount( 1, $revisions );
+		$this->assertCount( 2, $revisions );
 		foreach ( $revisions as $revision ) {
 			$this->assertTrue( user_can( self::$editor_user_id, 'edit_post', $revision->post_parent ) );
 		}
@@ -300,7 +300,7 @@ public function test_revision_diff_caps_post() {
 
 		// Diff checks if you can read both left and right revisions.
 		$revisions = wp_get_post_revisions( $post_id );
-		$this->assertCount( 2, $revisions );
+		$this->assertCount( 3, $revisions );
 		foreach ( $revisions as $revision ) {
 			$this->assertTrue( user_can( self::$editor_user_id, 'read_post', $revision->ID ) );
 		}
@@ -340,7 +340,7 @@ public function test_revision_view_caps_cpt() {
 		);
 
 		$revisions = wp_get_post_revisions( $post_id );
-		$this->assertCount( 1, $revisions );
+		$this->assertCount( 2, $revisions );
 		$this->assertTrue( user_can( self::$editor_user_id, 'read_post', $post_id ) );
 
 		foreach ( $revisions as $revision ) {
@@ -387,7 +387,7 @@ public function test_revision_restore_caps_cpt() {
 		);
 
 		$revisions = wp_get_post_revisions( $post_id );
-		$this->assertCount( 1, $revisions );
+		$this->assertCount( 2, $revisions );
 		foreach ( $revisions as $revision ) {
 			$this->assertTrue( user_can( self::$editor_user_id, 'edit_post', $revision->post_parent ) );
 		}
@@ -436,7 +436,7 @@ public function test_revision_restore_caps_before_publish() {
 		);
 
 		$revisions = wp_get_post_revisions( $post_id );
-		$this->assertCount( 1, $revisions );
+		$this->assertCount( 2, $revisions );
 		foreach ( $revisions as $revision ) {
 			$this->assertTrue( current_user_can( 'edit_post', $revision->post_parent ) );
 			$this->assertTrue( current_user_can( 'edit_post', $revision->ID ) );
@@ -451,7 +451,7 @@ public function test_revision_restore_caps_before_publish() {
 		);
 
 		$revisions = wp_get_post_revisions( $post_id );
-		$this->assertCount( 2, $revisions );
+		$this->assertCount( 3, $revisions );
 		foreach ( $revisions as $revision ) {
 			$this->assertFalse( current_user_can( 'edit_post', $revision->post_parent ) );
 			$this->assertFalse( current_user_can( 'edit_post', $revision->ID ) );
@@ -495,7 +495,7 @@ public function test_revision_diff_caps_cpt() {
 
 		// Diff checks if you can read both left and right revisions.
 		$revisions = wp_get_post_revisions( $post_id );
-		$this->assertCount( 2, $revisions );
+		$this->assertCount( 3, $revisions );
 		foreach ( $revisions as $revision ) {
 			$this->assertTrue( user_can( self::$editor_user_id, 'read_post', $revision->ID ) );
 		}
@@ -539,6 +539,8 @@ public function test_wp_get_post_revisions_should_order_by_post_date() {
 
 		$revisions = wp_get_post_revisions( $post['ID'] );
 
+		array_unshift( $revision_ids, reset( $revisions )->ID );
+
 		$this->assertSame( $revision_ids, array_values( wp_list_pluck( $revisions, 'ID' ) ) );
 	}
 
@@ -574,6 +576,8 @@ public function test_wp_get_post_revisions_should_order_by_ID_when_post_date_mat
 
 		$revisions = wp_get_post_revisions( $post['ID'] );
 
+		array_unshift( $revision_ids, reset( $revisions )->ID );
+
 		$this->assertSame( $revision_ids, array_values( wp_list_pluck( $revisions, 'ID' ) ) );
 	}
 
@@ -655,6 +659,149 @@ public function test_wp_save_post_revision_error() {
 		$this->assertWPError( $revision );
 	}
 
+	/**
+	 * Tests that wp_insert_post() saves the initial revision.
+	 *
+	 * @ticket 30854
+	 */
+	public function test_wp_insert_post_saves_initial_revision() {
+		$post_id = self::factory()->post->create(
+			array(
+				'post_title'   => 'Initial title',
+				'post_content' => 'Initial content',
+				'post_excerpt' => 'Initial excerpt',
+				'post_status'  => 'publish',
+			)
+		);
+
+		$revisions = wp_get_post_revisions( $post_id );
+
+		$this->assertCount( 1, $revisions, 'Initial revision should be created.' );
+		$this->assertContains(
+			'Initial content',
+			wp_list_pluck( $revisions, 'post_content' ),
+			'Initial revision should preserve the inserted content.'
+		);
+	}
+
+	/**
+	 * Tests that wp_insert_post() saves the initial revision for custom post statuses.
+	 *
+	 * @ticket 30854
+	 */
+	public function test_wp_insert_post_saves_initial_revision_for_custom_post_status() {
+		global $wp_post_statuses;
+
+		register_post_status( 'test-revision-status' );
+
+		try {
+			$post_id = self::factory()->post->create(
+				array(
+					'post_title'   => 'Initial title',
+					'post_content' => 'Initial content',
+					'post_status'  => 'test-revision-status',
+				)
+			);
+		} finally {
+			unset( $wp_post_statuses['test-revision-status'] );
+		}
+
+		$revisions = wp_get_post_revisions( $post_id );
+
+		$this->assertCount( 1, $revisions, 'Initial revision should be created.' );
+	}
+
+	/**
+	 * Tests the author for initial revisions.
+	 *
+	 * @ticket 30854
+	 */
+	public function test_wp_insert_post_saves_initial_revision_author() {
+		$old_user_id = get_current_user_id();
+
+		wp_set_current_user( 0 );
+		$no_current_user_post_id   = self::factory()->post->create(
+			array(
+				'post_author'  => self::$author_user_id,
+				'post_title'   => 'Initial title',
+				'post_content' => 'Initial content',
+				'post_status'  => 'publish',
+			)
+		);
+		$no_current_user_revisions = wp_get_post_revisions( $no_current_user_post_id );
+		$no_current_user_revision  = reset( $no_current_user_revisions );
+
+		wp_set_current_user( self::$admin_user_id );
+		$current_user_post_id   = self::factory()->post->create(
+			array(
+				'post_author'  => self::$author_user_id,
+				'post_title'   => 'Initial title',
+				'post_content' => 'Initial content',
+				'post_status'  => 'publish',
+			)
+		);
+		$current_user_revisions = wp_get_post_revisions( $current_user_post_id );
+		$current_user_revision  = reset( $current_user_revisions );
+
+		wp_set_current_user( $old_user_id );
+
+		$this->assertSame(
+			self::$author_user_id,
+			(int) $no_current_user_revision->post_author,
+			'Initial revision author should match the post author when there is no current user.'
+		);
+		$this->assertSame(
+			self::$admin_user_id,
+			(int) $current_user_revision->post_author,
+			'Initial revision author should match the current user.'
+		);
+	}
+
+	/**
+	 * Tests that wp_insert_post() does not save initial revisions when revisions should not be saved.
+	 *
+	 * @ticket 30854
+	 */
+	public function test_wp_insert_post_does_not_save_initial_revision_when_revisions_should_not_be_saved() {
+		$auto_draft_post_id = self::factory()->post->create(
+			array(
+				'post_title'   => 'Auto draft title',
+				'post_content' => 'Auto draft content',
+				'post_status'  => 'auto-draft',
+			)
+		);
+
+		remove_post_type_support( 'post', 'revisions' );
+		try {
+			$unsupported_post_id = self::factory()->post->create(
+				array(
+					'post_title'   => 'No revision title',
+					'post_content' => 'No revision content',
+					'post_status'  => 'publish',
+				)
+			);
+		} finally {
+			add_post_type_support( 'post', 'revisions' );
+		}
+
+		remove_action( 'post_updated', 'wp_save_post_revision', 10 );
+		try {
+			$action_removed_post_id = self::factory()->post->create(
+				array(
+					'post_title'   => 'No revision title',
+					'post_content' => 'No revision content',
+					'post_status'  => 'publish',
+				)
+			);
+		} finally {
+			add_action( 'post_updated', 'wp_save_post_revision', 10, 1 );
+		}
+
+		$this->assertCount( 0, wp_get_post_revisions( $auto_draft_post_id ), 'Auto-drafts should not save initial revisions.' );
+		$this->assertCount( 0, wp_get_post_revisions( $unsupported_post_id ), 'Post types without revision support should not save initial revisions.' );
+		$this->assertCount( 0, wp_get_post_revisions( $action_removed_post_id ), 'Removing the default revision action should disable initial revisions.' );
+	}
+
 	/**
 	 * Tests that wp_get_latest_revision_id_and_total_count() returns the latest revision ID and total count.
 	 *
@@ -724,25 +871,20 @@ public function test_wp_get_latest_revision_id_and_total_count_no_revisions() {
 	public function test_wp_get_post_revisions_url( $revisions ) {
 		wp_set_current_user( self::$admin_user_id );
 
-		$post_id            = self::factory()->post->create( array( 'post_title' => 'Some Post' ) );
-		$latest_revision_id = null;
-
-		if ( 0 !== $revisions ) {
-			$latest_revision_id = $post_id;
-
-			for ( $i = 0; $i < $revisions; ++$i ) {
-				wp_update_post(
-					array(
-						'ID'         => $post_id,
-						'post_title' => 'Some Post ' . $i,
-					)
-				);
+		$post_id = self::factory()->post->create( array( 'post_title' => 'Some Post' ) );
 
-				++$latest_revision_id;
-			}
+		for ( $i = 0; $i < $revisions; ++$i ) {
+			wp_update_post(
+				array(
+					'ID'         => $post_id,
+					'post_title' => 'Some Post ' . $i,
+				)
+			);
 		}
 
-		$expected = admin_url( 'revision.php?revision=' . $latest_revision_id );
+		$post_revisions  = wp_get_post_revisions( $post_id );
+		$latest_revision = reset( $post_revisions );
+		$expected        = admin_url( 'revision.php?revision=' . $latest_revision->ID );
 
 		$this->assertSame(
 			$expected,
@@ -752,7 +894,7 @@ public function test_wp_get_post_revisions_url( $revisions ) {
 
 		$this->assertSame(
 			$expected,
-			wp_get_post_revisions_url( $latest_revision_id ),
+			wp_get_post_revisions_url( $latest_revision->ID ),
 			'Failed when passed the latest revision ID'
 		);
 	}
@@ -772,25 +914,20 @@ public function test_wp_get_post_revisions_url( $revisions ) {
 	public function test_wp_get_post_revisions_url_with_post_object( $revisions ) {
 		wp_set_current_user( self::$admin_user_id );
 
-		$post               = self::factory()->post->create_and_get( array( 'post_title' => 'Some Post' ) );
-		$latest_revision_id = null;
+		$post = self::factory()->post->create_and_get( array( 'post_title' => 'Some Post' ) );
 
-		if ( 0 !== $revisions ) {
-			$latest_revision_id = $post->ID;
-
-			for ( $i = 0; $i < $revisions; ++$i ) {
-				wp_update_post(
-					array(
-						'ID'         => $post->ID,
-						'post_title' => 'Some Post ' . $i,
-					)
-				);
-
-				++$latest_revision_id;
-			}
+		for ( $i = 0; $i < $revisions; ++$i ) {
+			wp_update_post(
+				array(
+					'ID'         => $post->ID,
+					'post_title' => 'Some Post ' . $i,
+				)
+			);
 		}
 
-		$expected = admin_url( 'revision.php?revision=' . $latest_revision_id );
+		$post_revisions  = wp_get_post_revisions( $post->ID );
+		$latest_revision = reset( $post_revisions );
+		$expected        = admin_url( 'revision.php?revision=' . $latest_revision->ID );
 
 		$this->assertSame(
 			$expected,
@@ -800,7 +937,7 @@ public function test_wp_get_post_revisions_url_with_post_object( $revisions ) {
 
 		$this->assertSame(
 			$expected,
-			wp_get_post_revisions_url( $latest_revision_id ),
+			wp_get_post_revisions_url( $latest_revision->ID ),
 			'Failed when passed the latest revision ID'
 		);
 	}
@@ -839,7 +976,12 @@ public function test_wp_get_post_revisions_url_returns_null_when_post_does_not_e
 	 */
 	public function test_wp_get_post_revisions_url_returns_null_with_no_revisions() {
 		wp_set_current_user( self::$admin_user_id );
-		$post_id = self::factory()->post->create( array( 'post_title' => 'Some Post' ) );
+		$post_id = self::factory()->post->create(
+			array(
+				'post_title'  => 'Some Post',
+				'post_status' => 'auto-draft',
+			)
+		);
 		$this->assertNull( wp_get_post_revisions_url( $post_id ) );
 	}
 
@@ -925,7 +1067,7 @@ static function ( $revisions ) {
 		);
 
 		$this->assertSame(
-			'Test 57320 Update 1',
+			'Test 57320',
 			$second->post_title,
 			'The title of the second revision was incorrect.'
 		);
@@ -939,7 +1081,10 @@ public function test_wp_save_post_revision_with_array_post_meta() {
 		// This filter is true by default, but this is explicitly to test looking for differences among non-scalar fields.
 		add_filter( 'wp_save_post_revision_check_for_changes', '__return_true' );
 
-		$post_id  = self::factory()->post->create();
+		remove_action( 'wp_after_insert_post', 'wp_save_post_revision_on_insert', 9 );
+		$post_id = self::factory()->post->create();
+		add_action( 'wp_after_insert_post', 'wp_save_post_revision_on_insert', 9, 3 );
+
 		$meta_key = 'favorite_things';
 
 		// Ensure the post meta is saved with each revision.
diff --git a/tests/phpunit/tests/post/wpDeletePost.php b/tests/phpunit/tests/post/wpDeletePost.php
index 5382e496b7049..1b8e29f003d3d 100644
--- a/tests/phpunit/tests/post/wpDeletePost.php
+++ b/tests/phpunit/tests/post/wpDeletePost.php
@@ -159,7 +159,13 @@ static function () use ( $action, &$captured_action_args ) {
 			);
 		}
 
-		$post_id      = self::factory()->post->create();
+		remove_post_type_support( 'post', 'revisions' );
+		try {
+			$post_id = self::factory()->post->create();
+		} finally {
+			add_post_type_support( 'post', 'revisions' );
+		}
+
 		$deleted_post = wp_delete_post( (string) $post_id, true );
 		$this->assertInstanceOf( WP_Post::class, $deleted_post );
 
diff --git a/tests/phpunit/tests/rest-api/rest-global-styles-revisions-controller.php b/tests/phpunit/tests/rest-api/rest-global-styles-revisions-controller.php
index a715899979ad1..f84ee2c4c642c 100644
--- a/tests/phpunit/tests/rest-api/rest-global-styles-revisions-controller.php
+++ b/tests/phpunit/tests/rest-api/rest-global-styles-revisions-controller.php
@@ -211,17 +211,17 @@ public static function wpTearDownAfterClass() {
 	public function set_up() {
 		parent::set_up();
 		switch_theme( 'tt1-blocks' );
-		$revisions             = wp_get_post_revisions( self::$global_styles_id );
+		$revisions             = array_values( wp_get_post_revisions( self::$global_styles_id ) );
 		$this->total_revisions = count( $revisions );
 
-		$this->revision_1    = array_pop( $revisions );
-		$this->revision_1_id = $this->revision_1->ID;
+		$this->revision_3    = $revisions[0];
+		$this->revision_3_id = $this->revision_3->ID;
 
-		$this->revision_2    = array_pop( $revisions );
+		$this->revision_2    = $revisions[1];
 		$this->revision_2_id = $this->revision_2->ID;
 
-		$this->revision_3    = array_pop( $revisions );
-		$this->revision_3_id = $this->revision_3->ID;
+		$this->revision_1    = $revisions[2];
+		$this->revision_1_id = $this->revision_1->ID;
 	}
 
 	/**
@@ -961,8 +961,8 @@ public function test_get_global_styles_revisions_pagination() {
 		$this->assertSame( 200, $response->get_status() );
 		$data = $response->get_data();
 		$this->assertCount( 1, $data );
-		$this->assertSame( 3, $response->get_headers()['X-WP-Total'] );
-		$this->assertSame( 3, $response->get_headers()['X-WP-TotalPages'] );
+		$this->assertSame( 4, $response->get_headers()['X-WP-Total'] );
+		$this->assertSame( 4, $response->get_headers()['X-WP-TotalPages'] );
 
 		// Test paged.
 		$request = new WP_REST_Request( 'GET', '/wp/v2/global-styles/' . self::$global_styles_id . '/revisions' );
@@ -971,8 +971,8 @@ public function test_get_global_styles_revisions_pagination() {
 		$response = rest_get_server()->dispatch( $request );
 		$this->assertSame( 200, $response->get_status() );
 		$data = $response->get_data();
-		$this->assertCount( 1, $data );
-		$this->assertSame( 3, $response->get_headers()['X-WP-Total'] );
+		$this->assertCount( 2, $data );
+		$this->assertSame( 4, $response->get_headers()['X-WP-Total'] );
 		$this->assertSame( 2, $response->get_headers()['X-WP-TotalPages'] );
 
 		// Test out of bounds.
@@ -1347,7 +1347,7 @@ public function test_get_items_preserves_block_style_variations() {
 		$data     = $response->get_data();
 
 		$this->assertSame( 200, $response->get_status(), 'Response status should be 200.' );
-		$this->assertCount( 2, $data, 'Should have 2 revisions.' );
+		$this->assertCount( 3, $data, 'Should have 3 revisions.' );
 
 		// Verify first revision (most recent - orange).
 		$this->assertArrayHasKey(
diff --git a/tests/phpunit/tests/rest-api/rest-posts-controller.php b/tests/phpunit/tests/rest-api/rest-posts-controller.php
index 212ddde70dd83..7b298ae1de657 100644
--- a/tests/phpunit/tests/rest-api/rest-posts-controller.php
+++ b/tests/phpunit/tests/rest-api/rest-posts-controller.php
@@ -2250,9 +2250,12 @@ public function test_get_item_links() {
 		$replies_url = add_query_arg( 'post', self::$post_id, $replies_url );
 		$this->assertSame( $replies_url, $links['replies'][0]['href'] );
 
+		$revisions = wp_get_latest_revision_id_and_total_count( self::$post_id );
+
 		$this->assertSame( rest_url( '/wp/v2/posts/' . self::$post_id . '/revisions' ), $links['version-history'][0]['href'] );
-		$this->assertSame( 0, $links['version-history'][0]['attributes']['count'] );
-		$this->assertArrayNotHasKey( 'predecessor-version', $links );
+		$this->assertSame( 1, $links['version-history'][0]['attributes']['count'] );
+		$this->assertSame( rest_url( '/wp/v2/posts/' . self::$post_id . '/revisions/' . $revisions['latest_id'] ), $links['predecessor-version'][0]['href'] );
+		$this->assertSame( $revisions['latest_id'], $links['predecessor-version'][0]['attributes']['id'] );
 
 		$attachments_url = rest_url( '/wp/v2/media' );
 		$attachments_url = add_query_arg( 'parent', self::$post_id, $attachments_url );
@@ -2289,8 +2292,8 @@ public function test_get_item_links_predecessor() {
 				'ID'           => self::$post_id,
 			)
 		);
-		$revisions  = wp_get_post_revisions( self::$post_id );
-		$revision_1 = array_pop( $revisions );
+		$revisions       = wp_get_post_revisions( self::$post_id );
+		$latest_revision = reset( $revisions );
 
 		$request  = new WP_REST_Request( 'GET', sprintf( '/wp/v2/posts/%d', self::$post_id ) );
 		$response = rest_get_server()->dispatch( $request );
@@ -2298,10 +2301,10 @@ public function test_get_item_links_predecessor() {
 		$links = $response->get_links();
 
 		$this->assertSame( rest_url( '/wp/v2/posts/' . self::$post_id . '/revisions' ), $links['version-history'][0]['href'] );
-		$this->assertSame( 1, $links['version-history'][0]['attributes']['count'] );
+		$this->assertSame( 2, $links['version-history'][0]['attributes']['count'] );
 
-		$this->assertSame( rest_url( '/wp/v2/posts/' . self::$post_id . '/revisions/' . $revision_1->ID ), $links['predecessor-version'][0]['href'] );
-		$this->assertSame( $revision_1->ID, $links['predecessor-version'][0]['attributes']['id'] );
+		$this->assertSame( rest_url( '/wp/v2/posts/' . self::$post_id . '/revisions/' . $latest_revision->ID ), $links['predecessor-version'][0]['href'] );
+		$this->assertSame( $latest_revision->ID, $links['predecessor-version'][0]['attributes']['id'] );
 	}
 
 	public function test_get_item_links_no_author() {
diff --git a/tests/phpunit/tests/rest-api/rest-revisions-controller.php b/tests/phpunit/tests/rest-api/rest-revisions-controller.php
index 52011afcb9318..128e9e2a41954 100644
--- a/tests/phpunit/tests/rest-api/rest-revisions-controller.php
+++ b/tests/phpunit/tests/rest-api/rest-revisions-controller.php
@@ -23,6 +23,8 @@ class WP_Test_REST_Revisions_Controller extends WP_Test_REST_Controller_Testcase
 	private $revision_id2;
 	private $revision_3;
 	private $revision_id3;
+	private $revision_initial;
+	private $revision_initial_id;
 	private $revision_2_1_id;
 
 	public static function wpSetUpBeforeClass( WP_UnitTest_Factory $factory ) {
@@ -89,15 +91,17 @@ public function set_up() {
 		parent::set_up();
 
 		// Set first post revision vars.
-		$revisions             = wp_get_post_revisions( self::$post_id );
-		$this->total_revisions = count( $revisions );
-		$this->revisions       = $revisions;
-		$this->revision_1      = array_pop( $revisions );
-		$this->revision_id1    = $this->revision_1->ID;
-		$this->revision_2      = array_pop( $revisions );
-		$this->revision_id2    = $this->revision_2->ID;
-		$this->revision_3      = array_pop( $revisions );
-		$this->revision_id3    = $this->revision_3->ID;
+		$revisions                 = array_values( wp_get_post_revisions( self::$post_id ) );
+		$this->total_revisions     = count( $revisions );
+		$this->revisions           = $revisions;
+		$this->revision_3          = $revisions[0];
+		$this->revision_id3        = $this->revision_3->ID;
+		$this->revision_2          = $revisions[1];
+		$this->revision_id2        = $this->revision_2->ID;
+		$this->revision_1          = $revisions[2];
+		$this->revision_id1        = $this->revision_1->ID;
+		$this->revision_initial    = $revisions[3];
+		$this->revision_initial_id = $this->revision_initial->ID;
 
 		// Set second post revision vars.
 		$revisions             = wp_get_post_revisions( self::$post_id_2 );
@@ -160,6 +164,9 @@ public function test_get_items() {
 
 		$this->assertSame( $this->revision_id1, $data[2]['id'] );
 		$this->check_get_revision_response( $data[2], $this->revision_1 );
+
+		$this->assertSame( $this->revision_initial_id, $data[3]['id'] );
+		$this->check_get_revision_response( $data[3], $this->revision_initial );
 	}
 
 	/**
@@ -1070,7 +1077,7 @@ public function test_get_revisions_pagination() {
 		$response = rest_get_server()->dispatch( $request );
 		$this->assertSame( 200, $response->get_status() );
 		$data = $response->get_data();
-		$this->assertCount( 1, $data );
+		$this->assertCount( 2, $data );
 		$this->assertSame( $this->total_revisions, $response->get_headers()['X-WP-Total'] );
 		$this->assertSame( (int) ceil( $this->total_revisions / 2 ), $response->get_headers()['X-WP-TotalPages'] );
 
diff --git a/tests/phpunit/tests/rest-api/wpRestTemplateRevisionsController.php b/tests/phpunit/tests/rest-api/wpRestTemplateRevisionsController.php
index e8a18b275e7cd..957ec7dae83be 100644
--- a/tests/phpunit/tests/rest-api/wpRestTemplateRevisionsController.php
+++ b/tests/phpunit/tests/rest-api/wpRestTemplateRevisionsController.php
@@ -365,54 +365,31 @@ public function test_get_items_with_data_provider( $parent_post_property_name, $
 		$this->assertSame( WP_Http::OK, $response->get_status(), 'Response is expected to have a status code of 200.' );
 
 		$this->assertCount(
-			4,
+			5,
 			$revisions,
-			'Failed asserting that the response data contains exactly 4 items.'
+			'Failed asserting that the response data contains exactly 5 items.'
 		);
 
-		$this->assertSame(
-			$parent_post->ID,
-			$revisions[0]['parent'],
-			'Failed asserting that the parent ID of the revision matches the template post ID.'
-		);
-		$this->assertSame(
+		$expected_contents = array(
 			'Content revision #5',
-			$revisions[0]['content']['raw'],
-			'Failed asserting that the content of the revision is "Content revision #5".'
-		);
-
-		$this->assertSame(
-			$parent_post->ID,
-			$revisions[1]['parent'],
-			'Failed asserting that the parent ID of the revision matches the template post ID.'
-		);
-		$this->assertSame(
 			'Content revision #4',
-			$revisions[1]['content']['raw'],
-			'Failed asserting that the content of the revision is "Content revision #4".'
-		);
-
-		$this->assertSame(
-			$parent_post->ID,
-			$revisions[2]['parent'],
-			'Failed asserting that the parent ID of the revision matches the template post ID.'
-		);
-		$this->assertSame(
 			'Content revision #3',
-			$revisions[2]['content']['raw'],
-			'Failed asserting that the content of the revision is "Content revision #3".'
-		);
-
-		$this->assertSame(
-			$parent_post->ID,
-			$revisions[3]['parent'],
-			'Failed asserting that the parent ID of the revision matches the template post ID.'
-		);
-		$this->assertSame(
 			'Content revision #2',
-			$revisions[3]['content']['raw'],
-			'Failed asserting that the content of the revision is "Content revision #2".'
+			'Content',
 		);
+
+		foreach ( $expected_contents as $index => $expected_content ) {
+			$this->assertSame(
+				$parent_post->ID,
+				$revisions[ $index ]['parent'],
+				'Failed asserting that the parent ID of the revision matches the template post ID.'
+			);
+			$this->assertSame(
+				$expected_content,
+				$revisions[ $index ]['content']['raw'],
+				'Failed asserting that the revision content matches the expected content.'
+			);
+		}
 	}
 
 	/**
@@ -1199,8 +1176,8 @@ public function test_get_template_revisions_pagination() {
 		$this->assertSame( 200, $response->get_status() );
 		$data = $response->get_data();
 		$this->assertCount( 1, $data );
-		$this->assertSame( 4, $response->get_headers()['X-WP-Total'] );
-		$this->assertSame( 4, $response->get_headers()['X-WP-TotalPages'] );
+		$this->assertSame( 5, $response->get_headers()['X-WP-Total'] );
+		$this->assertSame( 5, $response->get_headers()['X-WP-TotalPages'] );
 
 		// Test paged.
 		$request = new WP_REST_Request( 'GET', '/wp/v2/templates/' . self::TEST_THEME . '/' . self::TEMPLATE_NAME . '/revisions' );
@@ -1210,8 +1187,8 @@ public function test_get_template_revisions_pagination() {
 		$this->assertSame( 200, $response->get_status() );
 		$data = $response->get_data();
 		$this->assertCount( 2, $data );
-		$this->assertSame( 4, $response->get_headers()['X-WP-Total'] );
-		$this->assertSame( 2, $response->get_headers()['X-WP-TotalPages'] );
+		$this->assertSame( 5, $response->get_headers()['X-WP-Total'] );
+		$this->assertSame( 3, $response->get_headers()['X-WP-TotalPages'] );
 
 		// Test out of bounds.
 		$request = new WP_REST_Request( 'GET', '/wp/v2/templates/' . self::TEST_THEME . '/' . self::TEMPLATE_NAME . '/revisions' );
diff --git a/tests/phpunit/tests/xmlrpc/wp/getRevisions.php b/tests/phpunit/tests/xmlrpc/wp/getRevisions.php
index 893a7a06dae93..43cf1459f1fa5 100644
--- a/tests/phpunit/tests/xmlrpc/wp/getRevisions.php
+++ b/tests/phpunit/tests/xmlrpc/wp/getRevisions.php
@@ -42,7 +42,7 @@ public function test_revision_count() {
 
 		$result = $this->myxmlrpcserver->wp_getRevisions( array( 1, 'editor', 'editor', $post_id ) );
 		$this->assertIsArray( $result );
-		$this->assertCount( 1, $result );
+		$this->assertCount( 2, $result );
 
 		wp_insert_post(
 			array(
@@ -53,7 +53,7 @@ public function test_revision_count() {
 
 		$result = $this->myxmlrpcserver->wp_getRevisions( array( 1, 'editor', 'editor', $post_id ) );
 		$this->assertIsArray( $result );
-		$this->assertCount( 2, $result );
+		$this->assertCount( 3, $result );
 	}
 
 	/**