diff --git a/typo3/sysext/backend/Configuration/SiteConfiguration/site_language.php b/typo3/sysext/backend/Configuration/SiteConfiguration/site_language.php
index fae1a1951c4f2b08a91e5f4e1e2e20578d436da3..1241ece6095088e243ae719e42a8092b59aaaa17 100644
--- a/typo3/sysext/backend/Configuration/SiteConfiguration/site_language.php
+++ b/typo3/sysext/backend/Configuration/SiteConfiguration/site_language.php
@@ -207,7 +207,7 @@ return [
                     ['eg', 'eg', 'flags-eg'],
                     ['eh', 'eh', 'flags-eh'],
                     ['en-us-gb', 'en-us-gb', 'flags-en-us-gb'],
-                    ['england', 'england', 'flags-gb-eng'],
+                    ['gb-eng', 'gb-eng', 'flags-gb-eng'],
                     ['er', 'er', 'flags-er'],
                     ['es', 'es', 'flags-es'],
                     ['et', 'et', 'flags-et'],
diff --git a/typo3/sysext/core/Documentation/Changelog/master/Important-91099-ChangedFlagIdentifierForEngland.rst b/typo3/sysext/core/Documentation/Changelog/master/Important-91099-ChangedFlagIdentifierForEngland.rst
new file mode 100644
index 0000000000000000000000000000000000000000..43c4332a68e8879a92f0a601265ce2120b2f6e9e
--- /dev/null
+++ b/typo3/sysext/core/Documentation/Changelog/master/Important-91099-ChangedFlagIdentifierForEngland.rst
@@ -0,0 +1,19 @@
+.. include:: ../../Includes.txt
+
+====================================================================
+Important: #91099 - Flag identifier changed for SiteLanguage England
+====================================================================
+
+See :issue:`91099`
+
+Description
+===========
+
+The flag identifier for England ("england") in the SiteLanguage was broken and resulted
+in a broken icon in the backend.
+To fix that issue the identifier has been changed ("gb-eng") and results in a proper icon.
+
+If you used this flag identifier in your Frontend setup, double check whether things are
+still working as desired.
+
+.. index:: Backend, ext:backend