diff --git a/core/config/schema/core.data_types.schema.yml b/core/config/schema/core.data_types.schema.yml
index 5b0b0fa..e0ba242 100644
--- a/core/config/schema/core.data_types.schema.yml
+++ b/core/config/schema/core.data_types.schema.yml
@@ -314,6 +314,11 @@ block_settings:
     provider:
       type: string
       label: 'Provider'
+    context_mapping:
+      type: sequence
+      label: 'Context assignments'
+      sequence:
+        type: string
 
 condition.plugin:
   type: mapping
diff --git a/core/lib/Drupal/Core/Block/BlockBase.php b/core/lib/Drupal/Core/Block/BlockBase.php
index 8a7fbfa..930d8ab 100644
--- a/core/lib/Drupal/Core/Block/BlockBase.php
+++ b/core/lib/Drupal/Core/Block/BlockBase.php
@@ -201,7 +201,7 @@ public function buildConfigurationForm(array $form, FormStateInterface $form_sta
       '#options' => $period,
     );
 
-    // Add context form elements.
+    // Add context mapping UI form elements.
     $contexts = $form_state->getTemporaryValue('gathered_contexts') ?: [];
     $form['context_mapping'] = $this->addContextAssignmentElement($this, $contexts);
     // Add plugin-specific settings for this block type.
diff --git a/core/lib/Drupal/Core/Plugin/ContextAwarePluginAssignmentTrait.php b/core/lib/Drupal/Core/Plugin/ContextAwarePluginAssignmentTrait.php
index e3ae261..c2d2dd8 100644
--- a/core/lib/Drupal/Core/Plugin/ContextAwarePluginAssignmentTrait.php
+++ b/core/lib/Drupal/Core/Plugin/ContextAwarePluginAssignmentTrait.php
@@ -65,7 +65,7 @@ protected function addContextAssignmentElement(ContextAwarePluginInterface $plug
 
         $assignments = $plugin->getContextMapping();
         $element[$context_slot] = [
-          '#title' => $definition->getLabel() ?: $context_slot,
+          '#title' => $definition->getLabel() ?: $this->t('Select a @context value:', ['@context' => $context_slot]),
           '#type' => 'select',
           '#options' => $options,
           '#required' => $definition->isRequired(),
diff --git a/core/modules/block/block.services.yml b/core/modules/block/block.services.yml
index ff4277d..5b6e521 100644
--- a/core/modules/block/block.services.yml
+++ b/core/modules/block/block.services.yml
@@ -9,4 +9,4 @@ services:
       - { name: event_subscriber }
   block.repository:
     class: Drupal\block\BlockRepository
-    arguments: ['@entity.manager', '@theme.manager', '@context.handler', '@context.repository']
+    arguments: ['@entity.manager', '@theme.manager']
diff --git a/core/modules/block/src/BlockForm.php b/core/modules/block/src/BlockForm.php
index e8035f4..605cf40 100644
--- a/core/modules/block/src/BlockForm.php
+++ b/core/modules/block/src/BlockForm.php
@@ -336,6 +336,7 @@ public function submitForm(array &$form, FormStateInterface $form_state) {
     // Call the plugin submit handler.
     $block = $entity->getPlugin();
     $block->submitConfigurationForm($form, $settings);
+    // If this block is context-aware, set the context mapping.
     if ($block instanceof ContextAwarePluginInterface && $block->getContextDefinitions()) {
       $context_mapping = $settings->getValue('context_mapping', []);
       $block->setContextMapping($context_mapping);
diff --git a/core/modules/block/src/BlockRepository.php b/core/modules/block/src/BlockRepository.php
index e9a5eb0..103557b 100644
--- a/core/modules/block/src/BlockRepository.php
+++ b/core/modules/block/src/BlockRepository.php
@@ -9,9 +9,6 @@
 
 use Drupal\Core\Cache\CacheableMetadata;
 use Drupal\Core\Entity\EntityManagerInterface;
-use Drupal\Core\Plugin\Context\ContextHandlerInterface;
-use Drupal\Core\Plugin\Context\ContextRepositoryInterface;
-use Drupal\Core\Plugin\ContextAwarePluginInterface;
 use Drupal\Core\Theme\ThemeManagerInterface;
 
 /**
@@ -34,36 +31,16 @@ class BlockRepository implements BlockRepositoryInterface {
   protected $themeManager;
 
   /**
-   * The context repository.
-   *
-   * @var \Drupal\Core\Plugin\Context\ContextRepositoryInterface
-   */
-  protected $contextRepository;
-
-  /**
-   * The context handler.
-   *
-   * @var \Drupal\Core\Plugin\Context\ContextHandlerInterface
-   */
-  protected $contextHandler;
-
-  /**
    * Constructs a new BlockRepository.
    *
    * @param \Drupal\Core\Entity\EntityManagerInterface $entity_manager
    *   The entity manager.
    * @param \Drupal\Core\Theme\ThemeManagerInterface $theme_manager
    *   The theme manager.
-   * @param \Drupal\Core\Plugin\Context\ContextHandlerInterface $context_handler
-   *   The plugin context handler.
-   * @param \Drupal\Core\Plugin\Context\ContextRepositoryInterface $context_repository
-   *   The context repository
    */
-  public function __construct(EntityManagerInterface $entity_manager, ThemeManagerInterface $theme_manager, ContextHandlerInterface $context_handler, ContextRepositoryInterface $context_repository) {
+  public function __construct(EntityManagerInterface $entity_manager, ThemeManagerInterface $theme_manager) {
     $this->blockStorage = $entity_manager->getStorage('block');
     $this->themeManager = $theme_manager;
-    $this->contextHandler = $context_handler;
-    $this->contextRepository = $context_repository;
   }
 
   /**
@@ -77,7 +54,6 @@ public function getVisibleBlocksPerRegion(array &$cacheable_metadata = []) {
     $full = array();
     foreach ($this->blockStorage->loadByProperties(array('theme' => $active_theme->getName())) as $block_id => $block) {
       /** @var \Drupal\block\BlockInterface $block */
-
       $access = $block->access('view', NULL, TRUE);
       $region = $block->getRegion();
       if (!isset($cacheable_metadata[$region])) {
diff --git a/core/modules/block/src/Tests/BlockUiTest.php b/core/modules/block/src/Tests/BlockUiTest.php
index 47fea2e..2206158 100644
--- a/core/modules/block/src/Tests/BlockUiTest.php
+++ b/core/modules/block/src/Tests/BlockUiTest.php
@@ -169,10 +169,16 @@ public function testCandidateBlockList() {
    * Tests the behavior of context-aware blocks.
    */
   public function testContextAwareBlocks() {
+    $expected_text = '<div id="test_context_aware--username">' . \Drupal::currentUser()->getUsername() . '</div>';
+    $this->drupalGet('');
+    $this->assertNoText('Test context-aware block');
+    $this->assertNoRaw($expected_text);
+
+    $block_url = 'admin/structure/block/add/test_context_aware/classy';
     $arguments = array(
       ':title' => 'Test context-aware block',
       ':category' => 'Block test',
-      ':href' => 'admin/structure/block/add/test_context_aware/classy',
+      ':href' => $block_url,
     );
     $pattern = '//tr[.//td/div[text()=:title] and .//td[text()=:category] and .//td//a[contains(@href, :href)]]';
 
@@ -182,6 +188,16 @@ public function testContextAwareBlocks() {
     $this->assertTrue(!empty($elements), 'The context-aware test block appears.');
     $definition = \Drupal::service('plugin.manager.block')->getDefinition('test_context_aware');
     $this->assertTrue(!empty($definition), 'The context-aware test block exists.');
+
+    $edit = [
+      'region' => 'content',
+      'settings[context_mapping][user]' => '@block_test.multiple_static_context:user2',
+    ];
+    $this->drupalPostForm($block_url, $edit, 'Save block');
+
+    $this->drupalGet('');
+    $this->assertText('Test context-aware block');
+    $this->assertRaw($expected_text);
   }
 
   /**
diff --git a/core/modules/block/tests/modules/block_test/block_test.services.yml b/core/modules/block/tests/modules/block_test/block_test.services.yml
new file mode 100644
index 0000000..f165a02
--- /dev/null
+++ b/core/modules/block/tests/modules/block_test/block_test.services.yml
@@ -0,0 +1,6 @@
+services:
+  block_test.multiple_static_context:
+    class: Drupal\block_test\ContextProvider\MultipleStaticContext
+    arguments: ['@current_user', '@entity.manager']
+    tags:
+      - { name: 'context_provider' }
diff --git a/core/modules/block/tests/modules/block_test/src/ContextProvider/MultipleStaticContext.php b/core/modules/block/tests/modules/block_test/src/ContextProvider/MultipleStaticContext.php
new file mode 100644
index 0000000..e316e8b
--- /dev/null
+++ b/core/modules/block/tests/modules/block_test/src/ContextProvider/MultipleStaticContext.php
@@ -0,0 +1,80 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\block_test\ContextProvider\MultipleStaticContext.
+ */
+
+namespace Drupal\block_test\ContextProvider;
+
+use Drupal\Core\Cache\CacheableMetadata;
+use Drupal\Core\Entity\EntityManagerInterface;
+use Drupal\Core\Plugin\Context\Context;
+use Drupal\Core\Plugin\Context\ContextDefinition;
+use Drupal\Core\Plugin\Context\ContextProviderInterface;
+use Drupal\Core\Session\AccountInterface;
+
+/**
+ * @todo.
+ */
+class MultipleStaticContext implements ContextProviderInterface {
+
+  /**
+   * The current user.
+   *
+   * @var \Drupal\Core\Session\AccountInterface
+   */
+  protected $account;
+
+  /**
+   * The user storage.
+   *
+   * @var \Drupal\user\UserStorageInterface
+   */
+  protected $userStorage;
+
+  /**
+   * Constructs a new MultipleStaticContext.
+   *
+   * @param \Drupal\Core\Session\AccountInterface $account
+   *   The current user.
+   * @param \Drupal\Core\Entity\EntityManagerInterface $entity_manager
+   *   The entity manager.
+   */
+  public function __construct(AccountInterface $account, EntityManagerInterface $entity_manager) {
+    $this->account = $account;
+    $this->userStorage = $entity_manager->getStorage('user');
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getRuntimeContexts(array $unqualified_context_ids) {
+    $current_user = $this->userStorage->load($this->account->id());
+
+    $context1 = new Context(new ContextDefinition('entity:user', 'User 1'));
+    $context1->setContextValue($current_user);
+
+    $context2 = new Context(new ContextDefinition('entity:user', 'User 2'));
+    $context2->setContextValue($current_user);
+
+    $cacheability = new CacheableMetadata();
+    $cacheability->setCacheContexts(['user']);
+
+    $context1->addCacheableDependency($cacheability);
+    $context2->addCacheableDependency($cacheability);
+
+    return [
+      'user1' => $context1,
+      'user2' => $context2,
+    ];
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getAvailableContexts() {
+    return $this->getRuntimeContexts([]);
+  }
+
+}
diff --git a/core/modules/block/tests/modules/block_test/src/Plugin/Block/TestContextAwareBlock.php b/core/modules/block/tests/modules/block_test/src/Plugin/Block/TestContextAwareBlock.php
index 56b127b..c4223d0 100644
--- a/core/modules/block/tests/modules/block_test/src/Plugin/Block/TestContextAwareBlock.php
+++ b/core/modules/block/tests/modules/block_test/src/Plugin/Block/TestContextAwareBlock.php
@@ -29,6 +29,8 @@ public function build() {
     /** @var $user \Drupal\user\UserInterface */
     $user = $this->getContextValue('user');
     return array(
+      '#prefix' => '<div id="' . $this->getPluginId() . '--username">',
+      '#suffix' => '</div>',
       '#markup' => $user->getUsername(),
     );
   }
diff --git a/core/modules/block/tests/src/Unit/BlockRepositoryTest.php b/core/modules/block/tests/src/Unit/BlockRepositoryTest.php
index 3fbf0db..83747de 100644
--- a/core/modules/block/tests/src/Unit/BlockRepositoryTest.php
+++ b/core/modules/block/tests/src/Unit/BlockRepositoryTest.php
@@ -10,7 +10,6 @@
 use Drupal\block\BlockRepository;
 use Drupal\Core\Access\AccessResult;
 use Drupal\Core\Block\BlockPluginInterface;
-use Drupal\Core\Plugin\Context\LazyContextRepository;
 use Drupal\Core\Plugin\ContextAwarePluginInterface;
 use Drupal\Tests\UnitTestCase;
 
@@ -36,16 +35,6 @@ class BlockRepositoryTest extends UnitTestCase {
   protected $theme;
 
   /**
-   * @var \Drupal\Core\Plugin\Context\ContextHandlerInterface|\PHPUnit_Framework_MockObject_MockObject
-   */
-  protected $contextHandler;
-
-  /**
-   * @var \Drupal\Core\Plugin\Context\LazyContextRepository|\Prophecy\Prophecy\ProphecyInterface
-   */
-  protected $contextRepository;
-
-  /**
    * {@inheritdoc}
    */
   protected function setUp() {
@@ -70,15 +59,13 @@ protected function setUp() {
       ->method('getActiveTheme')
       ->will($this->returnValue($active_theme));
 
-    $this->contextHandler = $this->getMock('Drupal\Core\Plugin\Context\ContextHandlerInterface');
-    $this->contextRepository = $this->prophesize(LazyContextRepository::class);
     $this->blockStorage = $this->getMock('Drupal\Core\Entity\EntityStorageInterface');
     $entity_manager = $this->getMock('Drupal\Core\Entity\EntityManagerInterface');
     $entity_manager->expects($this->any())
       ->method('getStorage')
       ->willReturn($this->blockStorage);
 
-    $this->blockRepository = new BlockRepository($entity_manager, $theme_manager, $this->contextHandler, $this->contextRepository->reveal());
+    $this->blockRepository = new BlockRepository($entity_manager, $theme_manager);
   }
 
   /**