diff --git a/core/includes/bootstrap.inc b/core/includes/bootstrap.inc
index 6d7826e123eaf7f701756405739b3f3958983f12..311967e400208c65745759db4e1080e6b1681ada 100644
--- a/core/includes/bootstrap.inc
+++ b/core/includes/bootstrap.inc
@@ -6,7 +6,6 @@
  */
 
 use Drupal\Component\Utility\Crypt;
-use Drupal\Core\Logger\RfcLogLevel;
 use Drupal\Core\Test\TestDatabase;
 use Drupal\Core\Utility\Error;
 use Drupal\Core\StringTranslation\TranslatableMarkup;
@@ -104,51 +103,6 @@ function t($string, array $args = [], array $options = []) {
   return new TranslatableMarkup($string, $args, $options);
 }
 
-/**
- * Logs an exception.
- *
- * This is a wrapper logging function which automatically decodes an exception.
- *
- * @param $type
- *   The category to which this message belongs.
- * @param $exception
- *   The exception that is going to be logged.
- * @param $message
- *   The message to store in the log. If empty, a text that contains all useful
- *   information about the passed-in exception is used.
- * @param $variables
- *   Array of variables to replace in the message on display or
- *   NULL if message is already translated or not possible to
- *   translate.
- * @param $severity
- *   The severity of the message, as per RFC 3164.
- * @param $link
- *   A link to associate with the message.
- *
- * @see \Drupal\Core\Utility\Error::decodeException()
- *
- * @deprecated in drupal:10.1.0 and is removed from drupal:11.0.0. Use
- *   Use \Drupal\Core\Utility\Error::logException() instead.
- *
- * @see https://www.drupal.org/node/2932520
- */
-function watchdog_exception($type, Exception $exception, $message = NULL, $variables = [], $severity = RfcLogLevel::ERROR, $link = NULL) {
-  @trigger_error('watchdog_exception() is deprecated in drupal:10.1.0 and is removed from drupal:11.0.0. Use \Drupal\Core\Utility\Error::logException() instead. See https://www.drupal.org/node/2932520', E_USER_DEPRECATED);
-
-  // Use a default value if $message is not set.
-  if (empty($message)) {
-    $message = Error::DEFAULT_ERROR_MESSAGE;
-  }
-
-  if ($link) {
-    $variables['link'] = $link;
-  }
-
-  $variables += Error::decodeException($exception);
-
-  \Drupal::logger($type)->log($severity, $message, $variables);
-}
-
 /**
  * Provides custom PHP error handling.
  *
diff --git a/core/includes/common.inc b/core/includes/common.inc
index cabd3ceeb8f410bf63cda91f2e7746af87cba381..cf9a8b1ad13188dd876cffc5ee945c7334a68034 100644
--- a/core/includes/common.inc
+++ b/core/includes/common.inc
@@ -11,7 +11,6 @@
 use Drupal\Component\Utility\SortArray;
 use Drupal\Core\Cache\Cache;
 use Drupal\Core\DrupalKernel;
-use Drupal\Core\StringTranslation\ByteSizeMarkup;
 
 /**
  * @defgroup php_wrappers PHP wrapper functions
@@ -114,39 +113,6 @@
  */
 const JS_THEME = 100;
 
-/**
- * @defgroup format Formatting
- * @{
- * Functions to format numbers, strings, dates, etc.
- */
-
-/**
- * Generates a string representation for the given byte count.
- *
- * @param $size
- *   A size in bytes.
- * @param $langcode
- *   Optional language code to translate to a language other than what is used
- *   to display the page.
- *
- * @return \Drupal\Core\StringTranslation\TranslatableMarkup
- *   A translated string representation of the size.
- *
- * @deprecated in drupal:10.2.0 and is removed from drupal:11.0.0. Use
- *   \Drupal\Core\StringTranslation\ByteSizeMarkup::create($size, $langcode)
- *   instead.
- *
- * @see https://www.drupal.org/node/2999981
- */
-function format_size($size, $langcode = NULL) {
-  @trigger_error('format_size() is deprecated in drupal:10.2.0 and is removed from drupal:11.0.0. Use \Drupal\Core\StringTranslation\ByteSizeMarkup::create($size, $langcode) instead. See https://www.drupal.org/node/2999981', E_USER_DEPRECATED);
-  return ByteSizeMarkup::create($size ?? 0, $langcode);
-}
-
-/**
- * @} End of "defgroup format".
- */
-
 /**
  * Returns the base URL path (i.e., directory) of the Drupal installation.
  *
@@ -493,22 +459,6 @@ function drupal_flush_all_caches($kernel = NULL) {
   }
 }
 
-/**
- * Changes the dummy query string added to all CSS and JavaScript files.
- *
- * Changing the dummy query string appended to CSS and JavaScript files forces
- * all browsers to reload fresh files.
- *
- * @deprecated in drupal:10.2.0 and is removed from drupal:11.0.0. Use
- *   Use \Drupal\Core\Asset\AssetQueryStringInterface::reset() instead.
- *
- * @see https://www.drupal.org/node/3358337
- */
-function _drupal_flush_css_js() {
-  @trigger_error('_drupal_flush_css_js is deprecated in drupal:10.2.0 and is removed from drupal:11.0.0. Use \Drupal\Core\Asset\AssetQueryStringInterface::reset() instead. See https://www.drupal.org/node/3358337', E_USER_DEPRECATED);
-  \Drupal::service('asset.query_string')->reset();
-}
-
 /**
  * Assembles the Drupal Updater registry.
  *
diff --git a/core/includes/install.inc b/core/includes/install.inc
index 62aa02ef5af8df571b84a2c5769e8d165761b3c4..8eb0630b7b9cff09ddd6ff345a5c0257d59bf035 100644
--- a/core/includes/install.inc
+++ b/core/includes/install.inc
@@ -11,7 +11,6 @@
 use Drupal\Core\Extension\Dependency;
 use Drupal\Core\Extension\ExtensionDiscovery;
 use Drupal\Core\Installer\InstallerKernel;
-use Drupal\Core\Site\SettingsEditor;
 use Symfony\Component\HttpFoundation\RedirectResponse;
 
 /**
@@ -140,200 +139,6 @@ function drupal_install_profile_distribution_version() {
   }
 }
 
-/**
- * Replaces values in settings.php with values in the submitted array.
- *
- * This function replaces values in place if possible, even for
- * multidimensional arrays. This way the old settings do not linger,
- * overridden and also the doxygen on a value remains where it should be.
- *
- * @param $settings
- *   An array of settings that need to be updated. Multidimensional arrays
- *   are dumped up to a stdClass object. The object can have value, required
- *   and comment properties.
- *   @code
- *   $settings['settings']['config_sync_directory'] = (object) array(
- *     'value' => 'config_hash/sync',
- *     'required' => TRUE,
- *   );
- *   @endcode
- *   gets dumped as:
- *   @code
- *   $settings['config_sync_directory'] = 'config_hash/sync'
- *   @endcode
- *
- * @deprecated in drupal:10.1.0 and is removed from drupal:11.0.0. Use
- *   SettingsEditor::rewrite() instead. Note $settings_file argument becomes
- *   required and the first argument of the method.
- *
- * @see https://www.drupal.org/node/3244583
- * @see \Drupal\Core\Site\SettingsEditor::rewrite()
- */
-function drupal_rewrite_settings($settings = [], $settings_file = NULL) {
-  @trigger_error(__FUNCTION__ . '() is deprecated in drupal:10.1.0 and is removed from drupal:11.0.0. Use SettingsEditor::rewrite() instead. The order of the arguments has also changed: $settings_file is now required and is the first argument of the method. See https://www.drupal.org/node/3244583', E_USER_DEPRECATED);
-  SettingsEditor::rewrite(
-    $settings_file ?? \Drupal::getContainer()->getParameter('site.path') . '/settings.php',
-    $settings
-  );
-}
-
-/**
- * Helper for drupal_rewrite_settings().
- *
- * Checks whether this token represents a scalar or NULL.
- *
- * @param int $type
- *   The token type.
- * @param string $value
- *   The value of the token.
- *
- * @return bool
- *   TRUE if this token represents a scalar or NULL.
- *
- * @deprecated in drupal:10.1.0 and is removed from drupal:11.0.0. Use
- *   SettingsEditor::rewrite() instead. As internal API,
- *   _drupal_rewrite_settings_is_simple() may also be removed in a minor
- *   release.
- *
- * @see https://www.drupal.org/node/3244583
- * @see token_name()
- */
-function _drupal_rewrite_settings_is_simple($type, $value) {
-  @trigger_error(__FUNCTION__ . '() is deprecated in drupal:10.1.0 and is removed from drupal:11.0.0. Use SettingsEditor::rewrite() instead. As internal API, ' . __FUNCTION__ . '() may also be removed in a minor release. See https://www.drupal.org/node/3244583', E_USER_DEPRECATED);
-  $is_integer = $type == T_LNUMBER;
-  $is_float = $type == T_DNUMBER;
-  $is_string = $type == T_CONSTANT_ENCAPSED_STRING;
-  $is_boolean_or_null = $type == T_STRING && in_array(strtoupper($value), ['TRUE', 'FALSE', 'NULL']);
-  return $is_integer || $is_float || $is_string || $is_boolean_or_null;
-}
-
-/**
- * Helper for drupal_rewrite_settings().
- *
- * Checks whether this token represents a valid array index: a number or a
- * string.
- *
- * @param int $type
- *   The token type.
- *
- * @return bool
- *   TRUE if this token represents a number or a string.
- *
- * @deprecated in drupal:10.1.0 and is removed from drupal:11.0.0. Use
- *   SettingsEditor::rewrite() instead. As internal API,
- *   _drupal_rewrite_settings_is_array_index() may also be removed in a minor
- *   release.
- *
- * @see https://www.drupal.org/node/3244583
- * @see token_name()
- */
-function _drupal_rewrite_settings_is_array_index($type) {
-  @trigger_error(__FUNCTION__ . '() is deprecated in drupal:10.1.0 and is removed from drupal:11.0.0. Use SettingsEditor::rewrite() instead. As internal API, ' . __FUNCTION__ . '() may also be removed in a minor release. See https://www.drupal.org/node/3244583', E_USER_DEPRECATED);
-  $is_integer = $type == T_LNUMBER;
-  $is_float = $type == T_DNUMBER;
-  $is_string = $type == T_CONSTANT_ENCAPSED_STRING;
-  return $is_integer || $is_float || $is_string;
-}
-
-/**
- * Helper for drupal_rewrite_settings().
- *
- * Makes the new settings global.
- *
- * @param array|null $ref
- *   A reference to a nested index in $GLOBALS.
- * @param array|object $variable
- *   The nested value of the setting being copied.
- *
- * @deprecated in drupal:10.1.0 and is removed from drupal:11.0.0. Use
- *   SettingsEditor::rewrite() instead. As internal API,
- *   _drupal_rewrite_settings_global() may also be removed in a minor
- *   release.
- *
- * @see https://www.drupal.org/node/3244583
- */
-function _drupal_rewrite_settings_global(&$ref, $variable) {
-  @trigger_error(__FUNCTION__ . '() is deprecated in drupal:10.1.0 and is removed from drupal:11.0.0. Use SettingsEditor::rewrite() instead. As internal API, ' . __FUNCTION__ . '() may also be removed in a minor release. See https://www.drupal.org/node/3244583', E_USER_DEPRECATED);
-  if (is_object($variable)) {
-    $ref = $variable->value;
-  }
-  else {
-    foreach ($variable as $k => $v) {
-      _drupal_rewrite_settings_global($ref[$k], $v);
-    }
-  }
-}
-
-/**
- * Helper for drupal_rewrite_settings().
- *
- * Dump the relevant value properties.
- *
- * @param array|object $variable
- *   The container for variable values.
- * @param string $variable_name
- *   Name of variable.
- *
- * @return string
- *   A string containing valid PHP code of the variable suitable for placing
- *   into settings.php.
- *
- * @deprecated in drupal:10.1.0 and is removed from drupal:11.0.0. Use
- *   SettingsEditor::rewrite() instead. As internal API,
- *   _drupal_rewrite_settings_dump() may also be removed in a minor
- *   release.
- *
- * @see https://www.drupal.org/node/3244583
- */
-function _drupal_rewrite_settings_dump($variable, $variable_name) {
-  @trigger_error(__FUNCTION__ . '() is deprecated in drupal:10.1.0 and is removed from drupal:11.0.0. Use SettingsEditor::rewrite() instead. As internal API, ' . __FUNCTION__ . '() may also be removed in a minor release. See https://www.drupal.org/node/3244583', E_USER_DEPRECATED);
-  $return = '';
-  if (is_object($variable)) {
-    if (!empty($variable->required)) {
-      $return .= _drupal_rewrite_settings_dump_one($variable, "$variable_name = ", "\n");
-    }
-  }
-  else {
-    foreach ($variable as $k => $v) {
-      $return .= _drupal_rewrite_settings_dump($v, $variable_name . "['" . $k . "']");
-    }
-  }
-  return $return;
-}
-
-/**
- * Helper for drupal_rewrite_settings().
- *
- * Dump the value of a value property and adds the comment if it exists.
- *
- * @param object $variable
- *   A stdClass object with at least a value property.
- * @param string $prefix
- *   A string to prepend to the variable's value.
- * @param string $suffix
- *   A string to append to the variable's value.
- *
- * @return string
- *   A string containing valid PHP code of the variable suitable for placing
- *   into settings.php.
- *
- * @deprecated in drupal:10.1.0 and is removed from drupal:11.0.0. Use
- *   SettingsEditor::rewrite() instead. As internal API,
- *   _drupal_rewrite_settings_dump_one() may also be removed in a minor
- *   release.
- *
- * @see https://www.drupal.org/node/3244583
- */
-function _drupal_rewrite_settings_dump_one(\stdClass $variable, $prefix = '', $suffix = '') {
-  @trigger_error(__FUNCTION__ . '() is deprecated in drupal:10.1.0 and is removed from drupal:11.0.0. Use SettingsEditor::rewrite() instead. As internal API, ' . __FUNCTION__ . '() may also be removed in a minor release. See https://www.drupal.org/node/3244583', E_USER_DEPRECATED);
-  $return = $prefix . var_export($variable->value, TRUE) . ';';
-  if (!empty($variable->comment)) {
-    $return .= ' // ' . $variable->comment;
-  }
-  $return .= $suffix;
-  return $return;
-}
-
 /**
  * Verifies that all dependencies are met for a given installation profile.
  *
diff --git a/core/includes/module.inc b/core/includes/module.inc
index 02a4f5d41f3e65098e07f17bbf859db9f10f51ea..0bf495c2e257cb862649315ea2fac51c4fe9b5ba 100644
--- a/core/includes/module.inc
+++ b/core/includes/module.inc
@@ -5,58 +5,6 @@
  * API for loading and interacting with Drupal modules.
  */
 
-/**
- * Loads a module include file.
- *
- * Examples:
- * @code
- *   // Load node.admin.inc from the node module.
- *   module_load_include('inc', 'node', 'node.admin');
- *   // Load content_types.inc from the node module.
- *   module_load_include('inc', 'node', 'content_types');
- * @endcode
- *
- * Do not use this function to load an install file, use module_load_install()
- * instead. Do not use this function in a global context since it requires
- * Drupal to be fully bootstrapped, use require_once DRUPAL_ROOT . '/path/file'
- * instead.
- *
- * @param $type
- *   The include file's type (file extension).
- * @param $module
- *   The module to which the include file belongs.
- * @param $name
- *   (optional) The base file name (without the $type extension). If omitted,
- *   $module is used; i.e., resulting in "$module.$type" by default.
- *
- * @return bool|string
- *   The name of the included file, if successful; FALSE otherwise.
- *
- * @deprecated in drupal:9.4.0 and is removed from drupal:11.0.0.
- *   Use \Drupal::moduleHandler()->loadInclude($module, $type, $name = NULL).
- *   Note that including code from uninstalled extensions is no longer
- *   supported.
- *
- * @see https://www.drupal.org/node/2948698
- */
-function module_load_include($type, $module, $name = NULL) {
-  @trigger_error("module_load_include() is deprecated in drupal:9.4.0 and is removed from drupal:11.0.0. Instead, you should use \Drupal::moduleHandler()->loadInclude(). Note that including code from uninstalled extensions is no longer supported. See https://www.drupal.org/node/2948698", E_USER_DEPRECATED);
-  if (!isset($name)) {
-    $name = $module;
-  }
-
-  if (\Drupal::hasService('extension.list.module')) {
-    /** @var \Drupal\Core\Extension\ModuleExtensionList $module_list */
-    $module_list = \Drupal::service('extension.list.module');
-    $file = DRUPAL_ROOT . '/' . $module_list->getPath($module) . "/$name.$type";
-    if (is_file($file)) {
-      require_once $file;
-      return $file;
-    }
-  }
-  return FALSE;
-}
-
 /**
  * Sets weight of a particular module.
  *
diff --git a/core/includes/theme.inc b/core/includes/theme.inc
index f9a6f37adeb77cb358e94f96e8ac41289d7d7fbc..14cf4b0ce8ffe531261e45c616858e7fd2a74bbb 100644
--- a/core/includes/theme.inc
+++ b/core/includes/theme.inc
@@ -12,13 +12,8 @@
 use Drupal\Component\Serialization\Json;
 use Drupal\Component\Utility\Crypt;
 use Drupal\Component\Utility\Html;
-use Drupal\Component\Render\MarkupInterface;
-use Drupal\Core\Cache\CacheableDependencyInterface;
 use Drupal\Core\Config\Config;
 use Drupal\Core\Config\StorageException;
-use Drupal\Core\Render\AttachmentsInterface;
-use Drupal\Core\Render\BubbleableMetadata;
-use Drupal\Core\Render\RenderableInterface;
 use Drupal\Core\Template\Attribute;
 use Drupal\Core\Template\AttributeHelper;
 use Drupal\Core\Theme\ThemeSettings;
@@ -71,40 +66,6 @@
  * @} End of "defgroup content_flags".
  */
 
-/**
- * Gets the theme registry.
- *
- * @param bool $complete
- *   Optional boolean to indicate whether to return the complete theme registry
- *   array or an instance of the Drupal\Core\Utility\ThemeRegistry class.
- *   If TRUE, the complete theme registry array will be returned. This is useful
- *   if you want to foreach over the whole registry, use array_* functions or
- *   inspect it in a debugger. If FALSE, an instance of the
- *   Drupal\Core\Utility\ThemeRegistry class will be returned, this provides an
- *   ArrayObject which allows it to be accessed with array syntax and isset(),
- *   and should be more lightweight than the full registry. Defaults to TRUE.
- *
- * @return array|\Drupal\Core\Utility\ThemeRegistry
- *   The complete theme registry array, or an instance of the
- *   Drupal\Core\Utility\ThemeRegistry class.
- *
- * @deprecated in drupal:10.1.0 and is removed from drupal:11.0.0. Use
- *   theme.registry service methods get() or getRuntime() instead.
- *
- * @see https://www.drupal.org/node/3348850
- */
-function theme_get_registry($complete = TRUE) {
-  $theme_registry = \Drupal::service('theme.registry');
-  if ($complete) {
-    @trigger_error(__FUNCTION__ . '() is deprecated in drupal:10.1.0 and is removed from drupal:11.0.0. Use theme.registry service method get() instead. See https://www.drupal.org/node/3348850', E_USER_DEPRECATED);
-    return $theme_registry->get();
-  }
-  else {
-    @trigger_error(__FUNCTION__ . '() is deprecated in drupal:10.1.0 and is removed from drupal:11.0.0. Use theme.registry service method getRuntime() instead. See https://www.drupal.org/node/3348850', E_USER_DEPRECATED);
-    return $theme_registry->getRuntime();
-  }
-}
-
 /**
  * Returns an array of default theme features.
  *
@@ -120,22 +81,6 @@ function _system_default_theme_features() {
   ];
 }
 
-/**
- * Forces the system to rebuild the theme registry.
- *
- * This function should be called when modules are added to the system, or when
- * a dynamic system needs to add more theme hooks.
- *
- * @deprecated in drupal:10.1.0 and is removed from drupal:11.0.0. Use
- *   theme.registry service reset() method instead.
- *
- * @see https://www.drupal.org/node/3348853
- */
-function drupal_theme_rebuild() {
-  @trigger_error(__FUNCTION__ . '() is deprecated in drupal:10.1.0 and is removed from drupal:11.0.0. Use theme.registry service reset() method instead. See https://www.drupal.org/node/3348853', E_USER_DEPRECATED);
-  \Drupal::service('theme.registry')->reset();
-}
-
 /**
  * Allows themes and/or theme engines to easily discover overridden templates.
  *
@@ -337,87 +282,6 @@ function theme_get_setting($setting_name, $theme = NULL) {
   return $cache[$theme]->get($setting_name);
 }
 
-/**
- * Escapes and renders variables for theme functions.
- *
- * This method is used in theme functions to ensure that the result is safe for
- * output inside HTML fragments. This mimics the behavior of the auto-escape
- * functionality in Twig.
- *
- * Note: This function should be kept in sync with
- * \Drupal\Core\Template\TwigExtension::escapeFilter().
- *
- * @param mixed $arg
- *   The string, object, or render array to escape if needed.
- *
- * @return string
- *   The rendered string, safe for use in HTML. The string is not safe when used
- *   as any part of an HTML attribute name or value.
- *
- * @throws \Exception
- *   Thrown when an object is passed in which cannot be printed.
- *
- * @deprecated in drupal:10.1.0 and is removed from drupal:11.0.0. There is no
- *   replacement. Theme engines must handle escaping by themselves.
- *
- * @see https://www.drupal.org/node/3336253
- */
-function theme_render_and_autoescape($arg) {
-  @trigger_error('theme_render_and_autoescape() is deprecated in drupal:10.1.0 and is removed from drupal:11.0.0. There is no replacement. Theme engines must handle escaping by themselves. See https://www.drupal.org/node/3336253', E_USER_DEPRECATED);
-
-  // If it's a renderable, then it'll be up to the generated render array it
-  // returns to contain the necessary cacheability & attachment metadata. If
-  // it doesn't implement CacheableDependencyInterface or AttachmentsInterface
-  // then there is nothing to do here.
-  if (!($arg instanceof RenderableInterface) && ($arg instanceof CacheableDependencyInterface || $arg instanceof AttachmentsInterface)) {
-    $arg_bubbleable = [];
-    BubbleableMetadata::createFromObject($arg)
-      ->applyTo($arg_bubbleable);
-    \Drupal::service('renderer')->render($arg_bubbleable);
-  }
-
-  if ($arg instanceof MarkupInterface) {
-    return (string) $arg;
-  }
-  $return = NULL;
-
-  if (is_scalar($arg)) {
-    $return = (string) $arg;
-  }
-  elseif (is_object($arg)) {
-    if ($arg instanceof RenderableInterface) {
-      $arg = $arg->toRenderable();
-    }
-    elseif (method_exists($arg, '__toString')) {
-      $return = (string) $arg;
-    }
-    // You can't throw exceptions in the magic PHP __toString methods, see
-    // http://php.net/manual/language.oop5.magic.php#object.tostring so
-    // we also support a toString method.
-    elseif (method_exists($arg, 'toString')) {
-      $return = $arg->toString();
-    }
-    else {
-      throw new \Exception('Object of type ' . get_class($arg) . ' cannot be printed.');
-    }
-  }
-
-  // We have a string or an object converted to a string: Escape it!
-  if (isset($return)) {
-    return $return instanceof MarkupInterface ? $return : Html::escape($return);
-  }
-
-  // This is a normal render array, which is safe by definition, with special
-  // simple cases already handled.
-
-  // Early return if this element was pre-rendered (no need to re-render).
-  if (isset($arg['#printed']) && $arg['#printed'] == TRUE && isset($arg['#markup']) && strlen($arg['#markup']) > 0) {
-    return (string) $arg['#markup'];
-  }
-  $arg['#printed'] = FALSE;
-  return (string) \Drupal::service('renderer')->render($arg);
-}
-
 /**
  * Converts theme settings to configuration.
  *
diff --git a/core/lib/Drupal/Core/Form/EventSubscriber/FormAjaxSubscriber.php b/core/lib/Drupal/Core/Form/EventSubscriber/FormAjaxSubscriber.php
index 92fa49541754635c737d15f4f3a87268ad23c225..5c4d87536d7128187da69aed9a229f68e74d9bec 100644
--- a/core/lib/Drupal/Core/Form/EventSubscriber/FormAjaxSubscriber.php
+++ b/core/lib/Drupal/Core/Form/EventSubscriber/FormAjaxSubscriber.php
@@ -146,22 +146,6 @@ protected function getFormAjaxException(\Throwable $e) {
     return $exception;
   }
 
-  /**
-   * Wraps format_size()
-   *
-   * @return string
-   *   The formatted size.
-   *
-   * @deprecated in drupal:10.2.0 and is removed from drupal:11.0.0. Use
-   *   \Drupal\Core\StringTranslation\ByteSizeMarkup::create() instead.
-   *
-   * @see https://www.drupal.org/node/2999981
-   */
-  protected function formatSize($size) {
-    @trigger_error(__METHOD__ . '() is deprecated in drupal:10.2.0 and is removed from drupal:11.0.0. Use \Drupal\Core\StringTranslation\ByteSizeMarkup::create() instead. See https://www.drupal.org/node/2999981', E_USER_DEPRECATED);
-    return format_size($size);
-  }
-
   /**
    * {@inheritdoc}
    */
diff --git a/core/modules/file/file.field.inc b/core/modules/file/file.field.inc
deleted file mode 100644
index 3917276fc6c763fa5b8bd43e947dba765e73961b..0000000000000000000000000000000000000000
--- a/core/modules/file/file.field.inc
+++ /dev/null
@@ -1,8 +0,0 @@
-<?php
-
-/**
- * @file
- * Field module functionality for the File module.
- */
-
-@trigger_error(__FILE__ . ' is deprecated in drupal:10.2.0 and is removed from drupal:11.0.0. Functions have been moved to file.module. See https://www.drupal.org/node/3369330', E_USER_DEPRECATED);
diff --git a/core/modules/migrate/src/MigrateExecutable.php b/core/modules/migrate/src/MigrateExecutable.php
index 47b887f3762925afed6ca913351e838f300e9150..f4e026f0bbb8be21d8938e231b0f37ac1572ce78 100644
--- a/core/modules/migrate/src/MigrateExecutable.php
+++ b/core/modules/migrate/src/MigrateExecutable.php
@@ -620,24 +620,4 @@ protected function attemptMemoryReclaim() {
     return memory_get_usage();
   }
 
-  /**
-   * Generates a string representation for the given byte count.
-   *
-   * @param int $size
-   *   A size in bytes.
-   *
-   * @return string
-   *   A translated string representation of the size.
-   *
-   * @deprecated in drupal:10.2.0 and is removed from drupal:11.0.0. Use
-   *   \Drupal\Core\StringTranslation\ByteSizeMarkup::create($size, $langcode)
-   *   instead.
-   *
-   * @see https://www.drupal.org/node/2999981
-   */
-  protected function formatSize($size) {
-    @trigger_error(__METHOD__ . '() is deprecated in drupal:10.2.0 and is removed from drupal:11.0.0. Use \Drupal\Core\StringTranslation\ByteSizeMarkup::create($size, $langcode) instead. See https://www.drupal.org/node/2999981', E_USER_DEPRECATED);
-    return format_size($size);
-  }
-
 }
diff --git a/core/tests/Drupal/KernelTests/Core/Asset/LegacyAssetTest.php b/core/tests/Drupal/KernelTests/Core/Asset/LegacyAssetTest.php
deleted file mode 100644
index 63865a69e767f79037cea43352ff66e12f9feeba..0000000000000000000000000000000000000000
--- a/core/tests/Drupal/KernelTests/Core/Asset/LegacyAssetTest.php
+++ /dev/null
@@ -1,23 +0,0 @@
-<?php
-
-namespace Drupal\KernelTests\Core\Asset;
-
-use Drupal\KernelTests\KernelTestBase;
-
-/**
- * Tests deprecated asset functions.
- *
- * @group Asset
- * @group legacy
- */
-class LegacyAssetTest extends KernelTestBase {
-
-  /**
-   * Tests the deprecation.
-   */
-  public function testDeprecatedDrupalFlushCssJs(): void {
-    $this->expectDeprecation('_drupal_flush_css_js is deprecated in drupal:10.2.0 and is removed from drupal:11.0.0. Use \Drupal\Core\Asset\AssetQueryStringInterface::reset() instead. See https://www.drupal.org/node/3358337');
-    _drupal_flush_css_js();
-  }
-
-}
diff --git a/core/tests/Drupal/KernelTests/Core/Bootstrap/LegacyBootstrapTest.php b/core/tests/Drupal/KernelTests/Core/Bootstrap/LegacyBootstrapTest.php
deleted file mode 100644
index a9f506bad28f20c1aaa9754726dfa8d70dd6dcbd..0000000000000000000000000000000000000000
--- a/core/tests/Drupal/KernelTests/Core/Bootstrap/LegacyBootstrapTest.php
+++ /dev/null
@@ -1,37 +0,0 @@
-<?php
-
-namespace Drupal\KernelTests\Core\Bootstrap;
-
-use ColinODell\PsrTestLogger\TestLogger;
-use Drupal\Core\Logger\RfcLogLevel;
-use Drupal\Core\Utility\Error;
-use Drupal\KernelTests\KernelTestBase;
-
-/**
- * Tests legacy bootstrap functions.
- *
- * @group Bootstrap
- * @group legacy
- */
-class LegacyBootstrapTest extends KernelTestBase {
-
-  /**
-   * {@inheritdoc}
-   */
-  protected static $modules = ['system'];
-
-  /**
-   * Tests watchdog_exception() deprecation.
-   */
-  public function testWatchdogException(): void {
-    $logger = new TestLogger();
-    /** @var \Drupal\Core\Logger\LoggerChannelFactoryInterface $loggerFactory */
-    $loggerFactory = \Drupal::service('logger.factory');
-    $loggerFactory->addLogger($logger);
-    $this->expectDeprecation('watchdog_exception() is deprecated in drupal:10.1.0 and is removed from drupal:11.0.0. Use \Drupal\Core\Utility\Error::logException() instead. See https://www.drupal.org/node/2932520');
-    $e = new \RuntimeException("foo");
-    watchdog_exception('test', $e);
-    $this->assertTrue($logger->hasRecordThatContains(Error::DEFAULT_ERROR_MESSAGE, RfcLogLevel::ERROR));
-  }
-
-}
diff --git a/core/tests/Drupal/KernelTests/Core/Common/LegacyCommonTest.php b/core/tests/Drupal/KernelTests/Core/Common/LegacyCommonTest.php
deleted file mode 100644
index b4ca440472426cb9ab671b9c1dbe40359bf26cab..0000000000000000000000000000000000000000
--- a/core/tests/Drupal/KernelTests/Core/Common/LegacyCommonTest.php
+++ /dev/null
@@ -1,25 +0,0 @@
-<?php
-
-namespace Drupal\KernelTests\Core\Common;
-
-use Drupal\KernelTests\KernelTestBase;
-
-/**
- * Tests deprecated legacy functions in common.inc.
- *
- * @group Common
- * @group legacy
- */
-class LegacyCommonTest extends KernelTestBase {
-
-  /**
-   * Tests deprecation of the format_size() function.
-   */
-  public function testFormatSizeDeprecation(): void {
-    $this->expectDeprecation('format_size() is deprecated in drupal:10.2.0 and is removed from drupal:11.0.0. Use \Drupal\Core\StringTranslation\ByteSizeMarkup::create($size, $langcode) instead. See https://www.drupal.org/node/2999981');
-    $size = format_size(4053371676);
-    $this->assertEquals('3.77 GB', $size);
-    $this->assertEquals('@size GB', $size->getUntranslatedString());
-  }
-
-}
diff --git a/core/tests/Drupal/KernelTests/Core/Extension/ModuleLegacyTest.php b/core/tests/Drupal/KernelTests/Core/Extension/ModuleLegacyTest.php
deleted file mode 100644
index 58c89fcd028ea4c7223b20129952499b736c4667..0000000000000000000000000000000000000000
--- a/core/tests/Drupal/KernelTests/Core/Extension/ModuleLegacyTest.php
+++ /dev/null
@@ -1,25 +0,0 @@
-<?php
-
-namespace Drupal\KernelTests\Core\Extension;
-
-use Drupal\KernelTests\KernelTestBase;
-
-/**
- * Tests deprecations from module.inc file.
- *
- * @group legacy
- */
-class ModuleLegacyTest extends KernelTestBase {
-
-  /**
-   * Test deprecation of module_load_include() function.
-   */
-  public function testModuleLoadInclude() {
-    $this->assertFalse($this->container->get('module_handler')->moduleExists('module_test'), 'Ensure module is uninstalled so we test the ability to include uninstalled code.');
-    $this->expectDeprecation('module_load_include() is deprecated in drupal:9.4.0 and is removed from drupal:11.0.0. Instead, you should use \Drupal::moduleHandler()->loadInclude(). Note that including code from uninstalled extensions is no longer supported. See https://www.drupal.org/node/2948698');
-    $filename = module_load_include('inc', 'module_test', 'module_test.file');
-    $this->assertStringEndsWith("module_test.file.inc", $filename);
-
-  }
-
-}
diff --git a/core/tests/Drupal/KernelTests/Core/Site/LegacySettingsRewriteTest.php b/core/tests/Drupal/KernelTests/Core/Site/LegacySettingsRewriteTest.php
deleted file mode 100644
index f1e6e40844f0eb566f2fcdc7bdd273e005f28c3c..0000000000000000000000000000000000000000
--- a/core/tests/Drupal/KernelTests/Core/Site/LegacySettingsRewriteTest.php
+++ /dev/null
@@ -1,131 +0,0 @@
-<?php
-
-namespace Drupal\KernelTests\Core\Site;
-
-use Drupal\Core\Site\Settings;
-use Drupal\KernelTests\KernelTestBase;
-
-/**
- * Tests the drupal_rewrite_settings() function.
- *
- * @group system
- * @group legacy
- * @covers drupal_rewrite_settings
- */
-class LegacySettingsRewriteTest extends KernelTestBase {
-
-  /**
-   * Tests the drupal_rewrite_settings() function.
-   */
-  public function testDrupalRewriteSettings() {
-    include_once $this->root . '/core/includes/install.inc';
-    $site_path = $this->container->getParameter('site.path');
-    $tests = [
-      [
-        'original' => '$no_index_value_scalar = TRUE;',
-        'settings' => [
-          'no_index_value_scalar' => (object) [
-            'value' => FALSE,
-            'comment' => 'comment',
-          ],
-        ],
-        'expected' => '$no_index_value_scalar = false; // comment',
-      ],
-      [
-        'original' => '$no_index_value_scalar = TRUE;',
-        'settings' => [
-          'no_index_value_foo' => [
-            'foo' => [
-              'value' => (object) [
-                'value' => NULL,
-                'required' => TRUE,
-                'comment' => 'comment',
-              ],
-            ],
-          ],
-        ],
-        'expected' => <<<'EXPECTED'
-$no_index_value_scalar = TRUE;
-$no_index_value_foo['foo']['value'] = NULL; // comment
-EXPECTED
-      ],
-      [
-        'original' => '$no_index_value_array = array("old" => "value");',
-        'settings' => [
-          'no_index_value_array' => (object) [
-            'value' => FALSE,
-            'required' => TRUE,
-            'comment' => 'comment',
-          ],
-        ],
-        'expected' => '$no_index_value_array = array("old" => "value");
-$no_index_value_array = false; // comment',
-      ],
-      [
-        'original' => '$has_index_value_scalar["foo"]["bar"] = NULL;',
-        'settings' => [
-          'has_index_value_scalar' => [
-            'foo' => [
-              'bar' => (object) [
-                'value' => FALSE,
-                'required' => TRUE,
-                'comment' => 'comment',
-              ],
-            ],
-          ],
-        ],
-        'expected' => '$has_index_value_scalar["foo"]["bar"] = false; // comment',
-      ],
-      [
-        'original' => '$has_index_value_scalar["foo"]["bar"] = "foo";',
-        'settings' => [
-          'has_index_value_scalar' => [
-            'foo' => [
-              'value' => (object) [
-                'value' => ['value' => 2],
-                'required' => TRUE,
-                'comment' => 'comment',
-              ],
-            ],
-          ],
-        ],
-        'expected' => <<<'EXPECTED'
-$has_index_value_scalar["foo"]["bar"] = "foo";
-$has_index_value_scalar['foo']['value'] = array (
-  'value' => 2,
-); // comment
-EXPECTED
-      ],
-    ];
-    foreach ($tests as $test) {
-      $filename = Settings::get('file_public_path', $site_path . '/files') . '/mock_settings.php';
-      file_put_contents($filename, "<?php\n" . $test['original'] . "\n");
-      $this->expectDeprecation('drupal_rewrite_settings() is deprecated in drupal:10.1.0 and is removed from drupal:11.0.0. Use SettingsEditor::rewrite() instead. The order of the arguments has also changed: $settings_file is now required and is the first argument of the method. See https://www.drupal.org/node/3244583');
-      drupal_rewrite_settings($test['settings'], $filename);
-      $this->assertEquals("<?php\n" . $test['expected'] . "\n", file_get_contents($filename));
-    }
-
-    // Test that <?php gets added to the start of an empty settings file.
-    // Set the array of settings that will be written to the file.
-    $test = [
-      'settings' => [
-        'no_index' => (object) [
-          'value' => TRUE,
-          'required' => TRUE,
-        ],
-      ],
-      'expected' => '$no_index = true;',
-    ];
-    // Make an empty file.
-    $filename = Settings::get('file_public_path', $site_path . '/files') . '/mock_settings.php';
-    file_put_contents($filename, "");
-
-    $this->expectDeprecation('drupal_rewrite_settings() is deprecated in drupal:10.1.0 and is removed from drupal:11.0.0. Use SettingsEditor::rewrite() instead. The order of the arguments has also changed: $settings_file is now required and is the first argument of the method. See https://www.drupal.org/node/3244583');
-    // Write the setting to the file.
-    drupal_rewrite_settings($test['settings'], $filename);
-
-    // Check that the result is just the php opening tag and the settings.
-    $this->assertEquals("<?php\n" . $test['expected'] . "\n", file_get_contents($filename));
-  }
-
-}
diff --git a/core/tests/Drupal/KernelTests/Core/Theme/RegistryTest.php b/core/tests/Drupal/KernelTests/Core/Theme/RegistryTest.php
index d5f74801f7cd0f13c159ed88cfcde9c24e046d08..8fa5c578372f25a4206d8c5cbb2be6e2b24aa672 100644
--- a/core/tests/Drupal/KernelTests/Core/Theme/RegistryTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Theme/RegistryTest.php
@@ -275,34 +275,4 @@ public function testThemeTemplatesRegisteredByModules() {
     $this->assertEquals($expected, array_values($registry['theme_test_registered_by_module']['preprocess functions']));
   }
 
-  /**
-   * Tests deprecated drupal_theme_rebuild() function.
-   *
-   * @see drupal_theme_rebuild()
-   * @group legacy
-   */
-  public function testLegacyThemeRegistryRebuild() {
-    $registry = \Drupal::service('theme.registry');
-    $runtime = $registry->getRuntime();
-    $hooks = $registry->get();
-    $this->expectDeprecation('drupal_theme_rebuild() is deprecated in drupal:10.1.0 and is removed from drupal:11.0.0. Use theme.registry service reset() method instead. See https://www.drupal.org/node/3348853');
-    drupal_theme_rebuild();
-    $this->assertNotSame($runtime, $registry->getRuntime());
-    $this->assertSame($hooks, $registry->get());
-  }
-
-  /**
-   * Tests deprecated theme_get_registry function.
-   *
-   * @see theme_get_registry()
-   * @group legacy
-   */
-  public function testLegacyThemeGetRegistry() {
-    $registry = \Drupal::service('theme.registry');
-    $this->expectDeprecation('theme_get_registry() is deprecated in drupal:10.1.0 and is removed from drupal:11.0.0. Use theme.registry service method get() instead. See https://www.drupal.org/node/3348850');
-    $this->assertEquals($registry->get(), theme_get_registry());
-    $this->expectDeprecation('theme_get_registry() is deprecated in drupal:10.1.0 and is removed from drupal:11.0.0. Use theme.registry service method getRuntime() instead. See https://www.drupal.org/node/3348850');
-    $this->assertEquals($registry->getRuntime(), theme_get_registry(FALSE));
-  }
-
 }
diff --git a/core/tests/Drupal/KernelTests/Core/Theme/ThemeRenderAndAutoescapeTest.php b/core/tests/Drupal/KernelTests/Core/Theme/ThemeRenderAndAutoescapeTest.php
deleted file mode 100644
index 901be11a72f1b71e5236ecb2023f95735e5ae375..0000000000000000000000000000000000000000
--- a/core/tests/Drupal/KernelTests/Core/Theme/ThemeRenderAndAutoescapeTest.php
+++ /dev/null
@@ -1,133 +0,0 @@
-<?php
-
-namespace Drupal\KernelTests\Core\Theme;
-
-use Drupal\Component\Utility\Html;
-use Drupal\Core\GeneratedLink;
-use Drupal\Core\Link;
-use Drupal\Core\Render\RenderContext;
-use Drupal\Core\Render\Markup;
-use Drupal\Core\Url;
-use Drupal\KernelTests\KernelTestBase;
-
-/**
- * Tests the theme_render_and_autoescape() function.
- *
- * @group Theme
- * @group legacy
- * @group #slow
- */
-class ThemeRenderAndAutoescapeTest extends KernelTestBase {
-
-  /**
-   * {@inheritdoc}
-   */
-  protected static $modules = ['system'];
-
-  /**
-   * {@inheritdoc}
-   */
-  protected function setUp(): void {
-    parent::setUp();
-    $this->expectDeprecation('theme_render_and_autoescape() is deprecated in drupal:10.1.0 and is removed from drupal:11.0.0. There is no replacement. Theme engines must handle escaping by themselves. See https://www.drupal.org/node/3336253');
-  }
-
-  /**
-   * @dataProvider providerTestThemeRenderAndAutoescape
-   */
-  public function testThemeRenderAndAutoescape($arg, $expected) {
-    if (is_array($arg) && isset($arg['#type']) && $arg['#type'] === 'link') {
-      $arg = Link::createFromRoute($arg['#title'], $arg['#url']);
-    }
-
-    $context = new RenderContext();
-    // Use a closure here since we need to render with a render context.
-    $theme_render_and_autoescape = function () use ($arg) {
-      return theme_render_and_autoescape($arg);
-    };
-    /** @var \Drupal\Core\Render\RendererInterface $renderer */
-    $renderer = \Drupal::service('renderer');
-    $output = $renderer->executeInRenderContext($context, $theme_render_and_autoescape);
-    $this->assertEquals($expected, $output);
-    $this->assertIsString($output);
-  }
-
-  /**
-   * Provide test examples.
-   */
-  public static function providerTestThemeRenderAndAutoescape() {
-    return [
-      'empty string unchanged' => ['', ''],
-      'simple string unchanged' => ['ab', 'ab'],
-      'int (scalar) cast to string' => [111, '111'],
-      'float (scalar) cast to string' => [2.10, '2.1'],
-      '> is escaped' => ['>', '&gt;'],
-      'Markup EM tag is unchanged' => [Markup::create('<em>hi</em>'), '<em>hi</em>'],
-      'Markup SCRIPT tag is unchanged' => [Markup::create('<script>alert("hi");</script>'), '<script>alert("hi");</script>'],
-      'EM tag in string is escaped' => ['<em>hi</em>', Html::escape('<em>hi</em>')],
-      'type link render array is rendered' => [['#type' => 'link', '#title' => 'Text', '#url' => '<none>'], '<a href="">Text</a>'],
-      'type markup with EM tags is rendered' => [['#markup' => '<em>hi</em>'], '<em>hi</em>'],
-      'SCRIPT tag in string is escaped' => [
-        '<script>alert(123)</script>',
-        Html::escape('<script>alert(123)</script>'),
-      ],
-      'type plain_text render array EM tag is escaped' => [['#plain_text' => '<em>hi</em>'], Html::escape('<em>hi</em>')],
-      'type hidden render array is rendered' => [['#type' => 'hidden', '#name' => 'foo', '#value' => 'bar'], "<input type=\"hidden\" name=\"foo\" value=\"bar\" />\n"],
-    ];
-  }
-
-  /**
-   * Ensures invalid content is handled correctly.
-   */
-  public function testThemeEscapeAndRenderNotPrintable() {
-    $this->expectException(\Exception::class);
-    theme_render_and_autoescape(new NonPrintable());
-  }
-
-  /**
-   * Ensure cache metadata is bubbled when using theme_render_and_autoescape().
-   */
-  public function testBubblingMetadata() {
-    $link = new GeneratedLink();
-    $link->setGeneratedLink('<a href="http://example.com"></a>');
-    $link->addCacheTags(['foo']);
-    $link->addAttachments(['library' => ['system/base']]);
-
-    $context = new RenderContext();
-    // Use a closure here since we need to render with a render context.
-    $theme_render_and_autoescape = function () use ($link) {
-      return theme_render_and_autoescape($link);
-    };
-    /** @var \Drupal\Core\Render\RendererInterface $renderer */
-    $renderer = \Drupal::service('renderer');
-    $output = $renderer->executeInRenderContext($context, $theme_render_and_autoescape);
-    $this->assertEquals('<a href="http://example.com"></a>', $output);
-    /** @var \Drupal\Core\Render\BubbleableMetadata $metadata */
-    $metadata = $context->pop();
-    $this->assertEquals(['foo'], $metadata->getCacheTags());
-    $this->assertEquals(['library' => ['system/base']], $metadata->getAttachments());
-  }
-
-  /**
-   * Ensure cache metadata is bubbled when using theme_render_and_autoescape().
-   */
-  public function testBubblingMetadataWithRenderable() {
-    $link = new Link('', Url::fromRoute('<current>'));
-
-    $context = new RenderContext();
-    // Use a closure here since we need to render with a render context.
-    $theme_render_and_autoescape = function () use ($link) {
-      return theme_render_and_autoescape($link);
-    };
-    /** @var \Drupal\Core\Render\RendererInterface $renderer */
-    $renderer = \Drupal::service('renderer');
-    $output = $renderer->executeInRenderContext($context, $theme_render_and_autoescape);
-    $this->assertEquals('<a href="/' . urlencode('<none>') . '"></a>', $output);
-    /** @var \Drupal\Core\Render\BubbleableMetadata $metadata */
-    $metadata = $context->pop();
-    $this->assertEquals(['route'], $metadata->getCacheContexts());
-  }
-
-}
-
-class NonPrintable {}