diff --git a/CHANGES.md b/CHANGES.md
index b0244a16f..1fce34e72 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -1,3 +1,62 @@
+Synapse 1.56.0rc1 (2022-03-29)
+==============================
+
+Features
+--------
+
+- Allow modules to store already existing 3PID associations. ([\#12195](https://github.com/matrix-org/synapse/issues/12195))
+- Allow registering admin users using the module API. Contributed by Famedly. ([\#12250](https://github.com/matrix-org/synapse/issues/12250))
+
+
+Bugfixes
+--------
+
+- Fix a long-standing bug which caused the `/_matrix/federation/v1/state` and `.../state_ids` endpoints to return incorrect or invalid data when called for an event which we have stored as an "outlier". ([\#12087](https://github.com/matrix-org/synapse/issues/12087))
+- Fix a long-standing bug where events from ignored users were still considered for relations. ([\#12227](https://github.com/matrix-org/synapse/issues/12227), [\#12232](https://github.com/matrix-org/synapse/issues/12232), [\#12285](https://github.com/matrix-org/synapse/issues/12285))
+- Fix a bug introduced in v1.53.0 where an unnecessary query could be performed when fetching bundled aggregations for threads. ([\#12228](https://github.com/matrix-org/synapse/issues/12228))
+- Fix a bug introduced in Synapse 1.52 where admins could not deactivate and GDPR-erase a user if Synapse was configured with limits on avatars. ([\#12261](https://github.com/matrix-org/synapse/issues/12261))
+
+
+Improved Documentation
+----------------------
+
+- Fix the link to the module documentation in the legacy spam checker warning message. ([\#12231](https://github.com/matrix-org/synapse/issues/12231))
+- Remove incorrect prefixes in the worker documentation for some endpoints. ([\#12243](https://github.com/matrix-org/synapse/issues/12243))
+- Correct `check_username_for_spam` annotations and docs. ([\#12246](https://github.com/matrix-org/synapse/issues/12246))
+- Corrected Authentik OpenID typo, added helpful note for troubleshooting. Contributed by @IronTooch. ([\#12275](https://github.com/matrix-org/synapse/issues/12275))
+- HAProxy reverse proxy guide update to stop sending IPv4-mapped address to homeserver. Contributed by @villepeh. ([\#12279](https://github.com/matrix-org/synapse/issues/12279))
+
+
+Internal Changes
+----------------
+
+- Rename `shared_rooms` to `mutual_rooms` (MSC2666), as per proposal changes. ([\#12036](https://github.com/matrix-org/synapse/issues/12036))
+- Remove check on `update_user_directory` for shared rooms handler (MSC2666), and update/expand documentation. ([\#12038](https://github.com/matrix-org/synapse/issues/12038))
+- Refactor `create_new_client_event` to use a new parameter, `state_event_ids`, which accurately describes the usage with [MSC2716](https://github.com/matrix-org/matrix-doc/pull/2716) instead of abusing `auth_event_ids`. ([\#12083](https://github.com/matrix-org/synapse/issues/12083), [\#12304](https://github.com/matrix-org/synapse/issues/12304))
+- Refuse to start if registration is enabled without email, captcha, or token-based verification unless new config flag `enable_registration_without_verification` is set. ([\#12091](https://github.com/matrix-org/synapse/issues/12091))
+- Add tests for database transaction callbacks. ([\#12198](https://github.com/matrix-org/synapse/issues/12198))
+- Handle cancellation in `DatabasePool.runInteraction()`. ([\#12199](https://github.com/matrix-org/synapse/issues/12199))
+- Add missing type hints for cache storage. ([\#12216](https://github.com/matrix-org/synapse/issues/12216))
+- Clean-up logic around rebasing URLs for URL image previews. ([\#12219](https://github.com/matrix-org/synapse/issues/12219))
+- Add type hints to tests files. ([\#12224](https://github.com/matrix-org/synapse/issues/12224), [\#12240](https://github.com/matrix-org/synapse/issues/12240), [\#12256](https://github.com/matrix-org/synapse/issues/12256))
+- Use the `ignored_users` table in additional places instead of re-parsing the account data. ([\#12225](https://github.com/matrix-org/synapse/issues/12225))
+- Refactor the relations endpoints to add a `RelationsHandler`. ([\#12237](https://github.com/matrix-org/synapse/issues/12237))
+- Generate announcement links in the release script. ([\#12242](https://github.com/matrix-org/synapse/issues/12242))
+- Improve error message when dependencies check finds a broken installation. ([\#12244](https://github.com/matrix-org/synapse/issues/12244))
+- Add missing type hints for storage. ([\#12248](https://github.com/matrix-org/synapse/issues/12248), [\#12255](https://github.com/matrix-org/synapse/issues/12255))
+- Compress metrics HTTP resource when enabled. Contributed by Nick @ Beeper. ([\#12258](https://github.com/matrix-org/synapse/issues/12258))
+- Refuse to start if DB has non-`C` locale, unless config flag `allow_unsafe_db_locale` is set to true. ([\#12262](https://github.com/matrix-org/synapse/issues/12262), [\#12288](https://github.com/matrix-org/synapse/issues/12288))
+- Optionally include account validity expiration information to experimental [MSC3720](https://github.com/matrix-org/matrix-doc/pull/3720) account status responses. ([\#12266](https://github.com/matrix-org/synapse/issues/12266))
+- Use type stubs for `psycopg2`. ([\#12269](https://github.com/matrix-org/synapse/issues/12269))
+- Add a new cache `_get_membership_from_event_id` to speed up push rule calculations in large rooms. ([\#12272](https://github.com/matrix-org/synapse/issues/12272))
+- Re-enable Complement concurrency in CI. ([\#12283](https://github.com/matrix-org/synapse/issues/12283))
+- Remove unused test utilities. ([\#12291](https://github.com/matrix-org/synapse/issues/12291))
+- Enhance logging for inbound federation events. ([\#12301](https://github.com/matrix-org/synapse/issues/12301))
+- Improve type annotations for `execute_values`. ([\#12311](https://github.com/matrix-org/synapse/issues/12311))
+- Fix compatibility with the recently-released Jinja 3.1. ([\#12313](https://github.com/matrix-org/synapse/issues/12313))
+- Avoid trying to calculate the state at outlier events. ([\#12314](https://github.com/matrix-org/synapse/issues/12314))
+
+
 Synapse 1.55.2 (2022-03-24)
 ===========================
 
diff --git a/changelog.d/12036.misc b/changelog.d/12036.misc
deleted file mode 100644
index d2996730c..000000000
--- a/changelog.d/12036.misc
+++ /dev/null
@@ -1 +0,0 @@
-Rename `shared_rooms` to `mutual_rooms` (MSC2666), as per proposal changes.
\ No newline at end of file
diff --git a/changelog.d/12038.misc b/changelog.d/12038.misc
deleted file mode 100644
index e2a65726b..000000000
--- a/changelog.d/12038.misc
+++ /dev/null
@@ -1 +0,0 @@
-Remove check on `update_user_directory` for shared rooms handler (MSC2666), and update/expand documentation.
\ No newline at end of file
diff --git a/changelog.d/12083.misc b/changelog.d/12083.misc
deleted file mode 100644
index 88fd6b92e..000000000
--- a/changelog.d/12083.misc
+++ /dev/null
@@ -1 +0,0 @@
-Refactor `create_new_client_event` to use a new parameter, `state_event_ids`, which accurately describes the usage with [MSC2716](https://github.com/matrix-org/matrix-doc/pull/2716) instead of abusing `auth_event_ids`.
diff --git a/changelog.d/12087.bugfix b/changelog.d/12087.bugfix
deleted file mode 100644
index 6dacdddd0..000000000
--- a/changelog.d/12087.bugfix
+++ /dev/null
@@ -1 +0,0 @@
-Fix a long-standing bug which caused the `/_matrix/federation/v1/state` and `.../state_ids` endpoints to return incorrect or invalid data when called for an event which we have stored as an "outlier".
diff --git a/changelog.d/12091.misc b/changelog.d/12091.misc
deleted file mode 100644
index def44987b..000000000
--- a/changelog.d/12091.misc
+++ /dev/null
@@ -1 +0,0 @@
-Refuse to start if registration is enabled without email, captcha, or token-based verification unless new config flag `enable_registration_without_verification` is set.
diff --git a/changelog.d/12195.feature b/changelog.d/12195.feature
deleted file mode 100644
index e8bcb950a..000000000
--- a/changelog.d/12195.feature
+++ /dev/null
@@ -1 +0,0 @@
-Allow modules to store already existing 3PID associations.
diff --git a/changelog.d/12198.misc b/changelog.d/12198.misc
deleted file mode 100644
index 6b184a905..000000000
--- a/changelog.d/12198.misc
+++ /dev/null
@@ -1 +0,0 @@
-Add tests for database transaction callbacks.
diff --git a/changelog.d/12199.misc b/changelog.d/12199.misc
deleted file mode 100644
index 16dec1d26..000000000
--- a/changelog.d/12199.misc
+++ /dev/null
@@ -1 +0,0 @@
-Handle cancellation in `DatabasePool.runInteraction()`.
diff --git a/changelog.d/12216.misc b/changelog.d/12216.misc
deleted file mode 100644
index dc398ac1e..000000000
--- a/changelog.d/12216.misc
+++ /dev/null
@@ -1 +0,0 @@
-Add missing type hints for cache storage.
diff --git a/changelog.d/12219.misc b/changelog.d/12219.misc
deleted file mode 100644
index 607941409..000000000
--- a/changelog.d/12219.misc
+++ /dev/null
@@ -1 +0,0 @@
-Clean-up logic around rebasing URLs for URL image previews.
diff --git a/changelog.d/12224.misc b/changelog.d/12224.misc
deleted file mode 100644
index b67a701db..000000000
--- a/changelog.d/12224.misc
+++ /dev/null
@@ -1 +0,0 @@
-Add type hints to tests files.
diff --git a/changelog.d/12225.misc b/changelog.d/12225.misc
deleted file mode 100644
index 23105c727..000000000
--- a/changelog.d/12225.misc
+++ /dev/null
@@ -1 +0,0 @@
-Use the `ignored_users` table in additional places instead of re-parsing the account data.
diff --git a/changelog.d/12227.bugfix b/changelog.d/12227.bugfix
deleted file mode 100644
index 1a7dccf46..000000000
--- a/changelog.d/12227.bugfix
+++ /dev/null
@@ -1 +0,0 @@
-Fix a long-standing bug where events from ignored users were still considered for relations.
diff --git a/changelog.d/12228.bugfix b/changelog.d/12228.bugfix
deleted file mode 100644
index 475577713..000000000
--- a/changelog.d/12228.bugfix
+++ /dev/null
@@ -1 +0,0 @@
-Fix a bug introduced in v1.53.0 where an unnecessary query could be performed when fetching bundled aggregations for threads.
diff --git a/changelog.d/12231.doc b/changelog.d/12231.doc
deleted file mode 100644
index 16593d2b9..000000000
--- a/changelog.d/12231.doc
+++ /dev/null
@@ -1 +0,0 @@
-Fix the link to the module documentation in the legacy spam checker warning message.
diff --git a/changelog.d/12232.bugfix b/changelog.d/12232.bugfix
deleted file mode 100644
index 1a7dccf46..000000000
--- a/changelog.d/12232.bugfix
+++ /dev/null
@@ -1 +0,0 @@
-Fix a long-standing bug where events from ignored users were still considered for relations.
diff --git a/changelog.d/12237.misc b/changelog.d/12237.misc
deleted file mode 100644
index 41c9dcbd3..000000000
--- a/changelog.d/12237.misc
+++ /dev/null
@@ -1 +0,0 @@
-Refactor the relations endpoints to add a `RelationsHandler`.
diff --git a/changelog.d/12240.misc b/changelog.d/12240.misc
deleted file mode 100644
index c5b635679..000000000
--- a/changelog.d/12240.misc
+++ /dev/null
@@ -1 +0,0 @@
-Add type hints to tests files.
\ No newline at end of file
diff --git a/changelog.d/12242.misc b/changelog.d/12242.misc
deleted file mode 100644
index 38e7e0f7d..000000000
--- a/changelog.d/12242.misc
+++ /dev/null
@@ -1 +0,0 @@
-Generate announcement links in the release script.
diff --git a/changelog.d/12243.doc b/changelog.d/12243.doc
deleted file mode 100644
index b2031f0a4..000000000
--- a/changelog.d/12243.doc
+++ /dev/null
@@ -1 +0,0 @@
-Remove incorrect prefixes in the worker documentation for some endpoints.
diff --git a/changelog.d/12244.misc b/changelog.d/12244.misc
deleted file mode 100644
index 950d48e4c..000000000
--- a/changelog.d/12244.misc
+++ /dev/null
@@ -1 +0,0 @@
-Improve error message when dependencies check finds a broken installation.
\ No newline at end of file
diff --git a/changelog.d/12246.doc b/changelog.d/12246.doc
deleted file mode 100644
index e7fcc1b99..000000000
--- a/changelog.d/12246.doc
+++ /dev/null
@@ -1 +0,0 @@
-Correct `check_username_for_spam` annotations and docs.
\ No newline at end of file
diff --git a/changelog.d/12248.misc b/changelog.d/12248.misc
deleted file mode 100644
index 2b1290d1e..000000000
--- a/changelog.d/12248.misc
+++ /dev/null
@@ -1 +0,0 @@
-Add missing type hints for storage.
\ No newline at end of file
diff --git a/changelog.d/12250.feature b/changelog.d/12250.feature
deleted file mode 100644
index 29a272445..000000000
--- a/changelog.d/12250.feature
+++ /dev/null
@@ -1 +0,0 @@
-Allow registering admin users using the module API. Contributed by Famedly.
diff --git a/changelog.d/12255.misc b/changelog.d/12255.misc
deleted file mode 100644
index 2b1290d1e..000000000
--- a/changelog.d/12255.misc
+++ /dev/null
@@ -1 +0,0 @@
-Add missing type hints for storage.
\ No newline at end of file
diff --git a/changelog.d/12256.misc b/changelog.d/12256.misc
deleted file mode 100644
index c5b635679..000000000
--- a/changelog.d/12256.misc
+++ /dev/null
@@ -1 +0,0 @@
-Add type hints to tests files.
\ No newline at end of file
diff --git a/changelog.d/12258.misc b/changelog.d/12258.misc
deleted file mode 100644
index 80024c8e9..000000000
--- a/changelog.d/12258.misc
+++ /dev/null
@@ -1 +0,0 @@
-Compress metrics HTTP resource when enabled. Contributed by Nick @ Beeper.
diff --git a/changelog.d/12261.bugfix b/changelog.d/12261.bugfix
deleted file mode 100644
index 1bfde4c38..000000000
--- a/changelog.d/12261.bugfix
+++ /dev/null
@@ -1 +0,0 @@
-Fix a bug introduced in Synapse 1.52 where admins could not deactivate and GDPR-erase a user if Synapse was configured with limits on avatars.
diff --git a/changelog.d/12262.misc b/changelog.d/12262.misc
deleted file mode 100644
index 574ac4752..000000000
--- a/changelog.d/12262.misc
+++ /dev/null
@@ -1 +0,0 @@
-Refuse to start if DB has non-`C` locale, unless config flag `allow_unsafe_db_locale` is set to true.
\ No newline at end of file
diff --git a/changelog.d/12266.misc b/changelog.d/12266.misc
deleted file mode 100644
index 59e271837..000000000
--- a/changelog.d/12266.misc
+++ /dev/null
@@ -1 +0,0 @@
-Optionally include account validity expiration information to experimental [MSC3720](https://github.com/matrix-org/matrix-doc/pull/3720) account status responses.
diff --git a/changelog.d/12269.misc b/changelog.d/12269.misc
deleted file mode 100644
index ed79cbb52..000000000
--- a/changelog.d/12269.misc
+++ /dev/null
@@ -1 +0,0 @@
-Use type stubs for `psycopg2`.
diff --git a/changelog.d/12272.misc b/changelog.d/12272.misc
deleted file mode 100644
index 95589f336..000000000
--- a/changelog.d/12272.misc
+++ /dev/null
@@ -1 +0,0 @@
-Add a new cache `_get_membership_from_event_id` to speed up push rule calculations in large rooms.
diff --git a/changelog.d/12275.doc b/changelog.d/12275.doc
deleted file mode 100644
index 2e26ad21e..000000000
--- a/changelog.d/12275.doc
+++ /dev/null
@@ -1 +0,0 @@
-Corrected Authentik OpenID typo, added helpful note for troubleshooting. Contributed by @IronTooch.
diff --git a/changelog.d/12279.doc b/changelog.d/12279.doc
deleted file mode 100644
index ca07104c9..000000000
--- a/changelog.d/12279.doc
+++ /dev/null
@@ -1 +0,0 @@
-HAProxy reverse proxy guide update to stop sending IPv4-mapped address to homeserver. Contributed by @villepeh.
diff --git a/changelog.d/12283.misc b/changelog.d/12283.misc
deleted file mode 100644
index e9f220850..000000000
--- a/changelog.d/12283.misc
+++ /dev/null
@@ -1 +0,0 @@
-Re-enable Complement concurrency in CI.
diff --git a/changelog.d/12285.bugfix b/changelog.d/12285.bugfix
deleted file mode 100644
index 1a7dccf46..000000000
--- a/changelog.d/12285.bugfix
+++ /dev/null
@@ -1 +0,0 @@
-Fix a long-standing bug where events from ignored users were still considered for relations.
diff --git a/changelog.d/12288.misc b/changelog.d/12288.misc
deleted file mode 100644
index ee8fbfd29..000000000
--- a/changelog.d/12288.misc
+++ /dev/null
@@ -1 +0,0 @@
-Refuse to start if DB has non-`C` locale, unless config flag `allow_unsafe_db_locale` is set to true.
diff --git a/changelog.d/12291.misc b/changelog.d/12291.misc
deleted file mode 100644
index b55dd68f9..000000000
--- a/changelog.d/12291.misc
+++ /dev/null
@@ -1 +0,0 @@
-Remove unused test utilities.
diff --git a/changelog.d/12301.misc b/changelog.d/12301.misc
deleted file mode 100644
index a4cd94ee5..000000000
--- a/changelog.d/12301.misc
+++ /dev/null
@@ -1 +0,0 @@
-Enhance logging for inbound federation events.
diff --git a/changelog.d/12304.misc b/changelog.d/12304.misc
deleted file mode 100644
index 88fd6b92e..000000000
--- a/changelog.d/12304.misc
+++ /dev/null
@@ -1 +0,0 @@
-Refactor `create_new_client_event` to use a new parameter, `state_event_ids`, which accurately describes the usage with [MSC2716](https://github.com/matrix-org/matrix-doc/pull/2716) instead of abusing `auth_event_ids`.
diff --git a/changelog.d/12311.misc b/changelog.d/12311.misc
deleted file mode 100644
index df0e824a7..000000000
--- a/changelog.d/12311.misc
+++ /dev/null
@@ -1 +0,0 @@
-Improve type annotations for `execute_values`.
\ No newline at end of file
diff --git a/changelog.d/12313.misc b/changelog.d/12313.misc
deleted file mode 100644
index f59f6cdc4..000000000
--- a/changelog.d/12313.misc
+++ /dev/null
@@ -1 +0,0 @@
-Fix compatibility with the recently-released Jinja 3.1.
diff --git a/changelog.d/12314.misc b/changelog.d/12314.misc
deleted file mode 100644
index 9f333e718..000000000
--- a/changelog.d/12314.misc
+++ /dev/null
@@ -1 +0,0 @@
-Avoid trying to calculate the state at outlier events.
diff --git a/debian/changelog b/debian/changelog
index 3c899e602..d04954457 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,3 +1,9 @@
+matrix-synapse-py3 (1.56.0~rc1) stable; urgency=medium
+
+  * New synapse release 1.56.0~rc1.
+
+ -- Synapse Packaging team <packages@matrix.org>  Tue, 29 Mar 2022 10:40:50 +0100
+
 matrix-synapse-py3 (1.55.2) stable; urgency=medium
 
   * New synapse release 1.55.2.
diff --git a/synapse/__init__.py b/synapse/__init__.py
index 88aef1889..0960305d7 100644
--- a/synapse/__init__.py
+++ b/synapse/__init__.py
@@ -68,7 +68,7 @@ try:
 except ImportError:
     pass
 
-__version__ = "1.55.2"
+__version__ = "1.56.0rc1"
 
 if bool(os.environ.get("SYNAPSE_TEST_PATCH_LOG_CONTEXTS", False)):
     # We import here so that we don't have to install a bunch of deps when