diff -u b/core/core.services.yml b/core/core.services.yml
--- b/core/core.services.yml
+++ b/core/core.services.yml
@@ -80,7 +80,7 @@
     tags:
       - { name: persist }
       - { name: event_subscriber }
-    arguments: ['@config.storage', '@event_dispatcher', '@config.typed', '@language.default']
+    arguments: ['@config.storage', '@event_dispatcher', '@config.typed']
   config.installer:
     class: Drupal\Core\Config\ConfigInstaller
     arguments: ['@config.factory', '@config.storage', '@config.typed', '@entity.manager', '@event_dispatcher']
diff -u b/core/includes/install.core.inc b/core/includes/install.core.inc
--- b/core/includes/install.core.inc
+++ b/core/includes/install.core.inc
@@ -390,8 +390,7 @@
     $container->register('config.factory', 'Drupal\Core\Config\ConfigFactory')
       ->addArgument(new Reference('config.storage'))
       ->addArgument(new Reference('event_dispatcher'))
-      ->addArgument(new Reference('config.typed'))
-      ->addArgument(new Reference('language.default'));
+      ->addArgument(new Reference('config.typed'));
 
     // Register the 'language_manager' service.
     $container->register('language_manager', 'Drupal\Core\Language\LanguageManager')
diff -u b/core/lib/Drupal/Core/Config/ConfigFactory.php b/core/lib/Drupal/Core/Config/ConfigFactory.php
--- b/core/lib/Drupal/Core/Config/ConfigFactory.php
+++ b/core/lib/Drupal/Core/Config/ConfigFactory.php
@@ -83,16 +83,11 @@
    *   An event dispatcher instance to use for configuration events.
    * @param \Drupal\Core\Config\TypedConfigManager $typed_config
    *   The typed configuration manager.
-   * @param \Drupal\Core\Language\LanguageDefault
-   *   The default language service. This sets the initial language on the
-   *   config factory to the site's default. The language can be used to
-   *   override configuration data if language overrides are available.
    */
-  public function __construct(StorageInterface $storage, EventDispatcher $event_dispatcher, TypedConfigManager $typed_config, LanguageDefault $default_language) {
+  public function __construct(StorageInterface $storage, EventDispatcher $event_dispatcher, TypedConfigManager $typed_config) {
     $this->storage = $storage;
     $this->eventDispatcher = $event_dispatcher;
     $this->typedConfigManager = $typed_config;
-    $this->language = $default_language->get();
   }
 
   /**
@@ -146,7 +141,12 @@
 
         if ($this->canOverride($name)) {
           // Get and apply any language overrides.
-          $language_overrides = $this->storage->read($this->getLanguageConfigName($this->language->id, $name));
+          if ($this->language) {
+            $language_overrides = $this->storage->read($this->getLanguageConfigName($this->language->id, $name));
+          }
+          else {
+            $language_overrides = FALSE;
+          }
           if (is_array($language_overrides)) {
             $this->cache[$cache_key]->setLanguageOverride($language_overrides);
           }
@@ -322,7 +322,7 @@
     $can_override = $this->canOverride($name);
     $cache_key = $name . ':' . ($can_override ? 'overrides' : 'raw');
 
-    if ($can_override) {
+    if ($can_override && isset($this->language)) {
       $cache_key =  $cache_key . ':' . $this->language->id;
     }
     return $cache_key;
@@ -356,7 +356,7 @@
   }
 
   /**
-   * Set the language to be used in configuration overrides.
+   * Sets the language to be used in configuration overrides.
    *
    * @param \Drupal\Core\Language\Language $language
    *   The language object to be set on the config factory. Used to override
@@ -365,12 +365,28 @@
    * @return \Drupal\Core\Config\ConfigFactory
    *   The config factory object.
    */
-  public function setLanguage(Language $language) {
+  public function setLanguage(Language $language = NULL) {
     $this->language = $language;
     return $this;
   }
 
   /**
+   * Sets the language for configuration overrides using the default language.
+   *
+   * @param \Drupal\Core\Language\LanguageDefault $language_default
+   *   The default language service. This sets the initial language on the
+   *   config factory to the site's default. The language can be used to
+   *   override configuration data if language overrides are available.
+   *
+   * @return \Drupal\Core\Config\ConfigFactory
+   *   The config factory object.
+   */
+  public function setLanguageFromDefault(LanguageDefault $language_default) {
+    $this->language = $language_default->get();
+    return $this;
+  }
+
+  /**
    * Gets the language Used to override configuration.
    *
    * @return \Drupal\Core\Language\Language
@@ -393,9 +409,11 @@
    */
   public function getLanguageConfigNames(array $names) {
     $language_names = array();
-    foreach ($names as $name) {
-      if ($language_name = $this->getLanguageConfigName($this->language->id, $name)) {
-        $language_names[$name] = $language_name;
+    if (isset($this->language)) {
+      foreach ($names as $name) {
+        if ($language_name = $this->getLanguageConfigName($this->language->id, $name)) {
+          $language_names[$name] = $language_name;
+        }
       }
     }
     return $language_names;
diff -u b/core/lib/Drupal/Core/DrupalKernel.php b/core/lib/Drupal/Core/DrupalKernel.php
--- b/core/lib/Drupal/Core/DrupalKernel.php
+++ b/core/lib/Drupal/Core/DrupalKernel.php
@@ -518,8 +518,10 @@
     $container->setParameter('container.namespaces', $namespaces);
 
     // Store the default language values on the container. This is so that the
-    // default language can be configured and the configuration factory can
-    // depend on it.
+    // default language can be configured using the configuration factory. This
+    // avoids the circular dependencies that would created by
+    // \Drupal\language\LanguageServiceProvider::alter() and allows the default
+    // language to not be english in the installer.
     $system = BootstrapConfigStorageFactory::get()->read('system.site');
     $default_language_values = Language::$defaultValues;
     if ($default_language_values['id'] != $system['langcode']) {
diff -u b/core/lib/Drupal/Core/Language/LanguageManager.php b/core/lib/Drupal/Core/Language/LanguageManager.php
--- b/core/lib/Drupal/Core/Language/LanguageManager.php
+++ b/core/lib/Drupal/Core/Language/LanguageManager.php
@@ -93,6 +93,7 @@
    * {@inheritdoc}
    */
   public function reset($type = NULL) {
+    return $this;
   }
 
   /**
diff -u b/core/modules/config/lib/Drupal/config/Tests/ConfigLanguageOverride.php b/core/modules/config/lib/Drupal/config/Tests/ConfigLanguageOverride.php
--- b/core/modules/config/lib/Drupal/config/Tests/ConfigLanguageOverride.php
+++ b/core/modules/config/lib/Drupal/config/Tests/ConfigLanguageOverride.php
@@ -39,8 +39,16 @@
    * Tests locale override based on language.
    */
   function testConfigLanguageOverride() {
-    // The configuration factory always has the default language injected by the
-    // container.
+    // The default configuration factory does not have the default language
+    // injected unless the Language module is enabled.
+    $config = \Drupal::config('config_test.system');
+    $this->assertIdentical($config->get('foo'), 'bar');
+
+    // \Drupal\language\LanguageServiceProvider::alter() calls
+    // \Drupal\Core\Config\ConfigFactory::setLanguageFromDefault() to set the
+    // language when the Language module is enabled. This test ensures that
+    // english overrides work.
+    \Drupal::configFactory()->setLanguageFromDefault(\Drupal::service('language.default'));
     $config = \Drupal::config('config_test.system');
     $this->assertIdentical($config->get('foo'), 'en bar');
 
diff -u b/core/modules/language/lib/Drupal/language/ConfigurableLanguageManager.php b/core/modules/language/lib/Drupal/language/ConfigurableLanguageManager.php
--- b/core/modules/language/lib/Drupal/language/ConfigurableLanguageManager.php
+++ b/core/modules/language/lib/Drupal/language/ConfigurableLanguageManager.php
@@ -108,13 +108,6 @@
   /**
    * {@inheritdoc}
    */
-  public function initConfigOverrides() {
-    $this->configFactory->setLanguage($this->getCurrentLanguage());
-  }
-
-  /**
-   * {@inheritdoc}
-   */
   public function init() {
     if (!$this->initialized) {
       foreach ($this->getDefinedLanguageTypes() as $type) {
@@ -226,6 +219,7 @@
     elseif (isset($this->negotiatedLanguages[$type])) {
       unset($this->negotiatedLanguages[$type]);
     }
+    return $this;
   }
 
   /**
diff -u b/core/modules/language/lib/Drupal/language/LanguageServiceProvider.php b/core/modules/language/lib/Drupal/language/LanguageServiceProvider.php
--- b/core/modules/language/lib/Drupal/language/LanguageServiceProvider.php
+++ b/core/modules/language/lib/Drupal/language/LanguageServiceProvider.php
@@ -31,7 +31,8 @@
         ->addArgument(new Reference('language_manager'))
         ->addArgument(new Reference('language_negotiator'))
         ->addArgument(new Reference('string_translation'))
-        ->addArgument(new Reference('current_user'));
+        ->addArgument(new Reference('current_user'))
+        ->addArgument(new Reference('config.factory'));
 
       $container->register('path_processor_language', 'Drupal\language\HttpKernel\PathProcessorLanguage')
         ->addTag('path_processor_inbound', array('priority' => 300))
@@ -54,6 +55,11 @@
       ->addArgument(new Reference('module_handler'));
     if ($default_language_values = $this->getDefaultLanguageValues()) {
       $container->setParameter('language.default_values', $default_language_values);
+      // Ensure that configuration is can be localised if site is monolingual
+      // but the Language module is enabled. This will the case for monolingual
+      // sites not in english.
+      $definition = $container->getDefinition('config.factory');
+      $definition->addMethodCall('setLanguageFromDefault', array(new Reference('language.default')));
     }
   }
 
only in patch2:
unchanged:
--- a/core/lib/Drupal/Core/Language/LanguageManagerInterface.php
+++ b/core/lib/Drupal/Core/Language/LanguageManagerInterface.php
@@ -62,6 +62,9 @@ public function getCurrentLanguage($type = Language::TYPE_INTERFACE);
    *   (optional) The language type to reset as a string, e.g.,
    *   Language::TYPE_INTERFACE, or NULL to reset all language types. Defaults
    *   to NULL.
+   *
+   * @return \Drupal\Core\Language\LanguageManagerInterface
+   *   The language manager that has been reset.
    */
   public function reset($type = NULL);
 
only in patch2:
unchanged:
--- a/core/modules/config/lib/Drupal/config/Tests/ConfigLanguageOverrideWebTest.php
+++ b/core/modules/config/lib/Drupal/config/Tests/ConfigLanguageOverrideWebTest.php
@@ -65,6 +65,21 @@ function testSiteNameTranslation() {
     // @see \Drupal\Core\PathProcessor::processInbound()
     $this->drupalGet('xx');
     $this->assertText('XX site name');
+
+    // Set the xx language to be the default language and delete the english
+    // language so the site is no longer multi-lingual and confirm configuration
+    // overrides still work.
+    $language_manager = \Drupal::languageManager()->reset();
+    $this->assertTrue($language_manager->isMultilingual(), 'The test site is multilingual.');
+    $language = \Drupal::languageManager()->getLanguage('xx');
+    $language->default = TRUE;
+    language_save($language);
+    language_delete('en');
+    $this->assertFalse($language_manager->isMultilingual(), 'The test site is monolingual.');
+
+    $this->drupalGet('xx');
+    $this->assertText('XX site name');
+
   }
 
 }
only in patch2:
unchanged:
--- a/core/modules/language/lib/Drupal/language/ConfigurableLanguageManagerInterface.php
+++ b/core/modules/language/lib/Drupal/language/ConfigurableLanguageManagerInterface.php
@@ -78,9 +78,4 @@ public function saveLanguageTypesConfiguration(array $config);
    */
   public function updateLockedLanguageWeights();
 
-  /**
-   * Initializes per-language overrides for configuration.
-   */
-  public function initConfigOverrides();
-
 }
only in patch2:
unchanged:
--- a/core/modules/language/lib/Drupal/language/EventSubscriber/LanguageRequestSubscriber.php
+++ b/core/modules/language/lib/Drupal/language/EventSubscriber/LanguageRequestSubscriber.php
@@ -7,6 +7,7 @@
 
 namespace Drupal\language\EventSubscriber;
 
+use Drupal\Core\Config\ConfigFactory;
 use Drupal\Core\Language\Language;
 use Drupal\Core\Session\AccountInterface;
 use Drupal\Core\StringTranslation\Translator\TranslatorInterface;
@@ -51,6 +52,13 @@ class LanguageRequestSubscriber implements EventSubscriberInterface {
   protected $currentUser;
 
   /**
+   * The configuration factory.
+   *
+   * @var \Drupal\Core\Config\ConfigFactory
+   */
+  protected $configFactory;
+
+  /**
    * Constructs a LanguageRequestSubscriber object.
    *
    * @param \Drupal\language\ConfigurableLanguageManagerInterface $language_manager
@@ -61,12 +69,15 @@ class LanguageRequestSubscriber implements EventSubscriberInterface {
    *   The translation service.
    * @param \Drupal\Core\Session\AccountInterface $current_user
    *   The current active user.
+   * @param \Drupal\Core\Config\ConfigFactory $config_factory
+   *   The configuration factory.
    */
-  public function __construct(ConfigurableLanguageManagerInterface $language_manager, LanguageNegotiatorInterface $negotiator, TranslatorInterface $translation, AccountInterface $current_user) {
+  public function __construct(ConfigurableLanguageManagerInterface $language_manager, LanguageNegotiatorInterface $negotiator, TranslatorInterface $translation, AccountInterface $current_user, ConfigFactory $config_factory) {
     $this->languageManager = $language_manager;
     $this->negotiator = $negotiator;
     $this->translation = $translation;
     $this->currentUser = $current_user;
+    $this->configFactory = $config_factory;
   }
 
   /**
@@ -83,7 +94,7 @@ public function onKernelRequestLanguage(GetResponseEvent $event) {
       if ($this->languageManager instanceof ConfigurableLanguageManagerInterface) {
         $this->languageManager->setNegotiator($this->negotiator);
         $this->languageManager->setRequest($request);
-        $this->languageManager->initConfigOverrides();
+        $this->configFactory->setLanguage($this->languageManager->getCurrentLanguage());
       }
       // After the language manager has initialized, set the default langcode
       // for the string translations.