diff --git a/CHANGES.md b/CHANGES.md
index c0679159df4..ee658eda214 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -1,3 +1,64 @@
+# Synapse 1.104.0rc1 (2024-03-26)
+
+### Features
+
+- Add an OIDC config to specify extra parameters for the authorization grant URL. IT can be useful to pass an ACR value for example. ([\#16971](https://github.com/element-hq/synapse/issues/16971))
+- OIDC: try to JWT decode userinfo response if JSON parsing failed. ([\#16972](https://github.com/element-hq/synapse/issues/16972))
+
+### Bugfixes
+
+- Fix a bug which meant that, under certain circumstances, we might never retry sending events or to-device messages over federation after a failure. ([\#16925](https://github.com/element-hq/synapse/issues/16925))
+- Fix various long-standing bugs which could cause incorrect state to be returned from `/sync` in certain situations. ([\#16949](https://github.com/element-hq/synapse/issues/16949))
+- Fix case in which `m.fully_read` marker would not get updated. Contributed by @SpiritCroc. ([\#16990](https://github.com/element-hq/synapse/issues/16990))
+- Fix bug which did not retract a user's pending knocks at rooms when their account was deactivated. Contributed by @hanadi92. ([\#17010](https://github.com/element-hq/synapse/issues/17010))
+
+### Updates to the Docker image
+
+- Updated start.py to generate config using the correct user ID when running as root (fixes #16824, #15202). ([\#16978](https://github.com/element-hq/synapse/issues/16978))
+
+### Improved Documentation
+
+- Add a query to force a refresh of a remote user's device list to the "Useful SQL for Admins" documentation page. ([\#16892](https://github.com/element-hq/synapse/issues/16892))
+- Minor grammatical corrections to the upgrade documentation. ([\#16965](https://github.com/element-hq/synapse/issues/16965))
+- Fix the sort order for the documentation version picker, so that newer releases appear above older ones. ([\#16966](https://github.com/element-hq/synapse/issues/16966))
+- Remove recommendation for a specific poetry version from contributing guide. ([\#17002](https://github.com/element-hq/synapse/issues/17002))
+
+### Internal Changes
+
+- Improve lock performance when a lot of locks are all waiting for a single lock to be released. ([\#16840](https://github.com/element-hq/synapse/issues/16840))
+- Update power level default for public rooms (#16907). ([\#16907](https://github.com/element-hq/synapse/issues/16907))
+- Improve event validation (#16908). ([\#16908](https://github.com/element-hq/synapse/issues/16908))
+- Multi-worker-docker-container: disable log buffering. ([\#16919](https://github.com/element-hq/synapse/issues/16919))
+- Refactor state delta calculation in `/sync` handler. ([\#16929](https://github.com/element-hq/synapse/issues/16929))
+- Clarify docs for some room state functions. ([\#16950](https://github.com/element-hq/synapse/issues/16950))
+- Specify IP subnets in canonical form. ([\#16953](https://github.com/element-hq/synapse/issues/16953))
+- As done for SAML mapping provider, let's pass the module API to the OIDC one so the mapper can do more logic in its code. ([\#16974](https://github.com/element-hq/synapse/issues/16974))
+- Allow containers building on top of Synapse's Complement container is use the included PostgreSQL cluster. ([\#16985](https://github.com/element-hq/synapse/issues/16985))
+- Raise poetry-core version cap to 1.9.0. ([\#16986](https://github.com/element-hq/synapse/issues/16986))
+- Patch the db conn pool sooner in tests. ([\#17017](https://github.com/element-hq/synapse/issues/17017))
+
+
+
+### Updates to locked dependencies
+
+* Bump anyhow from 1.0.80 to 1.0.81. ([\#17009](https://github.com/element-hq/synapse/issues/17009))
+* Bump black from 23.10.1 to 24.2.0. ([\#16936](https://github.com/element-hq/synapse/issues/16936))
+* Bump cryptography from 41.0.7 to 42.0.5. ([\#16958](https://github.com/element-hq/synapse/issues/16958))
+* Bump dawidd6/action-download-artifact from 3.1.1 to 3.1.2. ([\#16960](https://github.com/element-hq/synapse/issues/16960))
+* Bump dawidd6/action-download-artifact from 3.1.2 to 3.1.4. ([\#17008](https://github.com/element-hq/synapse/issues/17008))
+* Bump jinja2 from 3.1.2 to 3.1.3. ([\#17005](https://github.com/element-hq/synapse/issues/17005))
+* Bump log from 0.4.20 to 0.4.21. ([\#16977](https://github.com/element-hq/synapse/issues/16977))
+* Bump mypy from 1.5.1 to 1.8.0. ([\#16901](https://github.com/element-hq/synapse/issues/16901))
+* Bump netaddr from 0.9.0 to 1.2.1. ([\#17006](https://github.com/element-hq/synapse/issues/17006))
+* Bump pydantic from 2.6.0 to 2.6.4. ([\#17004](https://github.com/element-hq/synapse/issues/17004))
+* Bump pyo3 from 0.20.2 to 0.20.3. ([\#16962](https://github.com/element-hq/synapse/issues/16962))
+* Bump ruff from 0.1.14 to 0.3.2. ([\#16994](https://github.com/element-hq/synapse/issues/16994))
+* Bump serde from 1.0.196 to 1.0.197. ([\#16963](https://github.com/element-hq/synapse/issues/16963))
+* Bump serde_json from 1.0.113 to 1.0.114. ([\#16961](https://github.com/element-hq/synapse/issues/16961))
+* Bump types-jsonschema from 4.21.0.20240118 to 4.21.0.20240311. ([\#17007](https://github.com/element-hq/synapse/issues/17007))
+* Bump types-psycopg2 from 2.9.21.16 to 2.9.21.20240311. ([\#16995](https://github.com/element-hq/synapse/issues/16995))
+* Bump types-pyopenssl from 23.3.0.0 to 24.0.0.20240311. ([\#17003](https://github.com/element-hq/synapse/issues/17003))
+
 # Synapse 1.103.0 (2024-03-19)
 
 No significant changes since 1.103.0rc1.
diff --git a/changelog.d/16840.misc b/changelog.d/16840.misc
deleted file mode 100644
index 1175e6de713..00000000000
--- a/changelog.d/16840.misc
+++ /dev/null
@@ -1 +0,0 @@
-Improve lock performance when a lot of locks are all waiting for a single lock to be released.
diff --git a/changelog.d/16892.doc b/changelog.d/16892.doc
deleted file mode 100644
index dd82b491126..00000000000
--- a/changelog.d/16892.doc
+++ /dev/null
@@ -1 +0,0 @@
-Add a query to force a refresh of a remote user's device list to the "Useful SQL for Admins" documentation page.
\ No newline at end of file
diff --git a/changelog.d/16907.misc b/changelog.d/16907.misc
deleted file mode 100644
index e3a7fad447a..00000000000
--- a/changelog.d/16907.misc
+++ /dev/null
@@ -1 +0,0 @@
-Update power level default for public rooms (#16907).
\ No newline at end of file
diff --git a/changelog.d/16908.misc b/changelog.d/16908.misc
deleted file mode 100644
index d13c59aa35e..00000000000
--- a/changelog.d/16908.misc
+++ /dev/null
@@ -1 +0,0 @@
-Improve event validation (#16908).
\ No newline at end of file
diff --git a/changelog.d/16919.misc b/changelog.d/16919.misc
deleted file mode 100644
index 2c76f253791..00000000000
--- a/changelog.d/16919.misc
+++ /dev/null
@@ -1 +0,0 @@
-Multi-worker-docker-container: disable log buffering.
diff --git a/changelog.d/16925.bugfix b/changelog.d/16925.bugfix
deleted file mode 100644
index 781cad4b5be..00000000000
--- a/changelog.d/16925.bugfix
+++ /dev/null
@@ -1 +0,0 @@
-Fix a bug which meant that, under certain circumstances, we might never retry sending events or to-device messages over federation after a failure.
diff --git a/changelog.d/16929.misc b/changelog.d/16929.misc
deleted file mode 100644
index 9489784e4a1..00000000000
--- a/changelog.d/16929.misc
+++ /dev/null
@@ -1,2 +0,0 @@
-Refactor state delta calculation in `/sync` handler.
-
diff --git a/changelog.d/16949.bugfix b/changelog.d/16949.bugfix
deleted file mode 100644
index 99ed435d75b..00000000000
--- a/changelog.d/16949.bugfix
+++ /dev/null
@@ -1 +0,0 @@
-Fix various long-standing bugs which could cause incorrect state to be returned from `/sync` in certain situations.
diff --git a/changelog.d/16950.misc b/changelog.d/16950.misc
deleted file mode 100644
index c5a0741c3bc..00000000000
--- a/changelog.d/16950.misc
+++ /dev/null
@@ -1 +0,0 @@
-Clarify docs for some room state functions.
diff --git a/changelog.d/16953.misc b/changelog.d/16953.misc
deleted file mode 100644
index 81abcc3df02..00000000000
--- a/changelog.d/16953.misc
+++ /dev/null
@@ -1 +0,0 @@
-Specify IP subnets in canonical form.
diff --git a/changelog.d/16965.doc b/changelog.d/16965.doc
deleted file mode 100644
index 36f8093298e..00000000000
--- a/changelog.d/16965.doc
+++ /dev/null
@@ -1 +0,0 @@
-Minor grammatical corrections to the upgrade documentation.
diff --git a/changelog.d/16966.doc b/changelog.d/16966.doc
deleted file mode 100644
index 06f4093aee1..00000000000
--- a/changelog.d/16966.doc
+++ /dev/null
@@ -1 +0,0 @@
-Fix the sort order for the documentation version picker, so that newer releases appear above older ones.
diff --git a/changelog.d/16971.feature b/changelog.d/16971.feature
deleted file mode 100644
index 9fdc88a3225..00000000000
--- a/changelog.d/16971.feature
+++ /dev/null
@@ -1 +0,0 @@
-Add an OIDC config to specify extra parameters for the authorization grant URL. IT can be useful to pass an ACR value for example.
diff --git a/changelog.d/16972.feature b/changelog.d/16972.feature
deleted file mode 100644
index 0f28cbbcd6e..00000000000
--- a/changelog.d/16972.feature
+++ /dev/null
@@ -1 +0,0 @@
-OIDC: try to JWT decode userinfo response if JSON parsing failed.
diff --git a/changelog.d/16974.misc b/changelog.d/16974.misc
deleted file mode 100644
index bf0a13786ce..00000000000
--- a/changelog.d/16974.misc
+++ /dev/null
@@ -1 +0,0 @@
-As done for SAML mapping provider, let's pass the module API to the OIDC one so the mapper can do more logic in its code.
diff --git a/changelog.d/16978.docker b/changelog.d/16978.docker
deleted file mode 100644
index 2e095c6aa9a..00000000000
--- a/changelog.d/16978.docker
+++ /dev/null
@@ -1 +0,0 @@
-Updated start.py to generate config using the correct user ID when running as root (fixes #16824, #15202).
diff --git a/changelog.d/16985.misc b/changelog.d/16985.misc
deleted file mode 100644
index 34d1337a281..00000000000
--- a/changelog.d/16985.misc
+++ /dev/null
@@ -1 +0,0 @@
-Allow containers building on top of Synapse's Complement container is use the included PostgreSQL cluster.
diff --git a/changelog.d/16986.misc b/changelog.d/16986.misc
deleted file mode 100644
index 0a556ba8b49..00000000000
--- a/changelog.d/16986.misc
+++ /dev/null
@@ -1 +0,0 @@
-Raise poetry-core version cap to 1.9.0.
diff --git a/changelog.d/16990.bugfix b/changelog.d/16990.bugfix
deleted file mode 100644
index 76f9dd2e36a..00000000000
--- a/changelog.d/16990.bugfix
+++ /dev/null
@@ -1 +0,0 @@
-Fix case in which `m.fully_read` marker would not get updated. Contributed by @SpiritCroc.
diff --git a/changelog.d/17002.doc b/changelog.d/17002.doc
deleted file mode 100644
index a1b2ce5e317..00000000000
--- a/changelog.d/17002.doc
+++ /dev/null
@@ -1 +0,0 @@
-Remove recommendation for a specific poetry version from contributing guide.
diff --git a/changelog.d/17010.bugfix b/changelog.d/17010.bugfix
deleted file mode 100644
index 0e1495f744f..00000000000
--- a/changelog.d/17010.bugfix
+++ /dev/null
@@ -1 +0,0 @@
-Fix bug which did not retract a user's pending knocks at rooms when their account was deactivated. Contributed by @hanadi92.
\ No newline at end of file
diff --git a/changelog.d/17017.misc b/changelog.d/17017.misc
deleted file mode 100644
index c8af23d67a7..00000000000
--- a/changelog.d/17017.misc
+++ /dev/null
@@ -1 +0,0 @@
-Patch the db conn pool sooner in tests.
diff --git a/debian/changelog b/debian/changelog
index c718dec7b00..b915b6e2cbb 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,3 +1,9 @@
+matrix-synapse-py3 (1.104.0~rc1) stable; urgency=medium
+
+  * New Synapse release 1.104.0rc1.
+
+ -- Synapse Packaging team <packages@matrix.org>  Tue, 26 Mar 2024 11:48:58 +0000
+
 matrix-synapse-py3 (1.103.0) stable; urgency=medium
 
   * New Synapse release 1.103.0.
diff --git a/pyproject.toml b/pyproject.toml
index 3bd5736755d..83691393015 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -96,7 +96,7 @@ module-name = "synapse.synapse_rust"
 
 [tool.poetry]
 name = "matrix-synapse"
-version = "1.103.0"
+version = "1.104.0rc1"
 description = "Homeserver for the Matrix decentralised comms protocol"
 authors = ["Matrix.org Team and Contributors <packages@matrix.org>"]
 license = "AGPL-3.0-or-later"