diff --git a/CHANGELOG.md b/CHANGELOG.md
index abaa1cb35..5de6cadf3 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,128 @@ documentation before upgrading to a new release.
Released closed milestones can be found on [GitHub](https://github.com/Icinga/icinga2/milestones?state=closed).
+## 2.13.0 (2021-08-03)
+
+[Issues and PRs](https://github.com/Icinga/icinga2/issues?utf8=%E2%9C%93&q=milestone%3A2.13.0)
+
+### Notes
+
+Upgrading docs: https://icinga.com/docs/icinga2/snapshot/doc/16-upgrading-icinga-2/#upgrading-to-v213
+
+Thanks to all contributors:
+[andygrunwald](https://github.com/Icinga/icinga2/pulls?q=is%3Apr+author%3Aandygrunwald+milestone%3A2.13.0),
+[BausPhi](https://github.com/Icinga/icinga2/pulls?q=is%3Apr+author%3ABausPhi+milestone%3A2.13.0),
+[bebehei](https://github.com/Icinga/icinga2/pulls?q=is%3Apr+author%3Abebehei+milestone%3A2.13.0),
+[Bobobo-bo-Bo-bobo](https://github.com/Icinga/icinga2/pulls?q=is%3Apr+author%3ABobobo-bo-Bo-bobo+milestone%3A2.13.0),
+[efuss](https://github.com/Icinga/icinga2/pulls?q=is%3Apr+author%3Aefuss+milestone%3A2.13.0),
+[froehl](https://github.com/Icinga/icinga2/pulls?q=is%3Apr+author%3Afroehl+milestone%3A2.13.0),
+[iustin](https://github.com/Icinga/icinga2/pulls?q=is%3Apr+author%3Aiustin+milestone%3A2.13.0),
+[JochenFriedrich](https://github.com/Icinga/icinga2/pulls?q=is%3Apr+author%3AJochenFriedrich+milestone%3A2.13.0),
+[leeclemens](https://github.com/Icinga/icinga2/pulls?q=is%3Apr+author%3Aleeclemens+milestone%3A2.13.0),
+[log1-c](https://github.com/Icinga/icinga2/pulls?q=is%3Apr+author%3Alog1-c+milestone%3A2.13.0),
+[lyknode](https://github.com/Icinga/icinga2/pulls?q=is%3Apr+author%3Alyknode+milestone%3A2.13.0),
+[m41kc0d3](https://github.com/Icinga/icinga2/pulls?q=is%3Apr+author%3Am41kc0d3+milestone%3A2.13.0),
+[MarcusCaepio](https://github.com/Icinga/icinga2/pulls?q=is%3Apr+author%3AMarcusCaepio+milestone%3A2.13.0),
+[mathiasaerts](https://github.com/Icinga/icinga2/pulls?q=is%3Apr+author%3Amathiasaerts+milestone%3A2.13.0),
+[mcktr](https://github.com/Icinga/icinga2/pulls?q=is%3Apr+author%3Amcktr+milestone%3A2.13.0),
+[MEschenbacher](https://github.com/Icinga/icinga2/pulls?q=is%3Apr+author%3AMEschenbacher+milestone%3A2.13.0),
+[Napsty](https://github.com/Icinga/icinga2/pulls?q=is%3Apr+author%3ANapsty+milestone%3A2.13.0),
+[netson](https://github.com/Icinga/icinga2/pulls?q=is%3Apr+author%3Anetson+milestone%3A2.13.0),
+[pdolinic](https://github.com/Icinga/icinga2/pulls?q=is%3Apr+author%3Apdolinic+milestone%3A2.13.0),
+[Ragnra](https://github.com/Icinga/icinga2/pulls?q=is%3Apr+author%3ARagnra+milestone%3A2.13.0),
+[RincewindsHat](https://github.com/Icinga/icinga2/pulls?q=is%3Apr+author%3ARincewindsHat+milestone%3A2.13.0),
+[sbraz](https://github.com/Icinga/icinga2/pulls?q=is%3Apr+author%3Asbraz+milestone%3A2.13.0),
+[sni](https://github.com/Icinga/icinga2/pulls?q=is%3Apr+author%3Asni+milestone%3A2.13.0),
+[sysadt](https://github.com/Icinga/icinga2/pulls?q=is%3Apr+author%3Asysadt+milestone%3A2.13.0),
+[XnS](https://github.com/Icinga/icinga2/pulls?q=is%3Apr+author%3AXnS+milestone%3A2.13.0),
+[yayayayaka](https://github.com/Icinga/icinga2/pulls?q=is%3Apr+author%3Ayayayayaka+milestone%3A2.13.0)
+
+### Enhancements
+
+* Core
+ * PerfdataValue: Add units of measurement #7871
+ * Flapping: Allow to ignore states in flapping detection #8600
+* Cluster
+ * Display log message if two nodes run on incompatible versions #8088
+* API
+ * /v1/actions/remove-downtime: Also remove child downtimes #8913
+ * Add API endpoint: /v1/actions/execute-command #8040
+ * /v1/actions/add-comment: Add param expiry #8035
+ * API-Event StateChange & CheckResult: Add acknowledgement and downtime_depth #7736
+ * Implement new API events ObjectCreated, ObjectDeleted and ObjectModified #8083
+ * Implement scheduling_endpoint attribute to checkable #6326
+* Windows
+ * Add support for Windows Event Log and write early log messages to it #8710
+* IDO
+ * MySQL: support larger host and service names #8425
+* ITL
+ * Add -S parameter for esxi_hardware ITL #8814
+ * Add CheckCommands for Thola #8683
+ * Add option ignore-sct for ssl_cert to ITL #8625
+ * Improve check_dns command when used with monitoring-plugins 2.3 #8589
+ * Add parameter -f to snmp-process #8569
+ * Add systemd CheckCommand #8568
+ * Add new options for ipmi-sensor #8498
+ * check_snmp_int: support -a #8003
+ * check_fail2ban: Add parameter fail2ban_jail to monitor a specific jail only #7960
+ * check_nrpe: Add parameters needed for PKI usage #7907
+* Metrics
+ * Support InfluxDB 2.0 #8719
+ * Add support for InfluxDB basic auth #8314
+* Docs
+ * Add info about ongoing support for IDO #8446
+ * Improve instructions on how to setup a Windows dev env #8400
+ * Improve instructions for installing wixtoolset on Windows #8397
+ * Add section about usage of satellites #8458
+ * Document command for verifying the parent node's certificate #8221
+ * Clarify TimePeriod/ScheduledDowntime time zone handling #8001
+* Misc
+ * Support TLS 1.3 #8718
+ * Livestatus: append app name to program_version #7931
+ * sd_notify() systemd about what we're doing right now #7874
+
+### Bugfixes
+
+* Core
+ * Fix state not being UNKNOWN after process timeout #8937
+ * Set a default severity for loggers #8846
+ * Fix integer overflow when converting large unsigned integers to string #8742
+ * StartUnixWorker(): don't exit() on fork() failure #8427
+ * Fix perf data parser not recognizing scientific notation #8492
+ * Close FDs based on /proc/self/fd #8442
+ * Fix check source getting overwritten on passive check result #8158
+ * Clean up temp files #8157
+ * Improve perf data parser to allow for special output (e.g. ASCII tables) #8008
+ * On check timeout first send SIGTERM #7918
+* Cluster
+ * Drop passive check results for unreachable hosts/services #8267
+ * Fix state timestamps set by the same check result differing across nodes #8101
+* API
+ * Do not override status codes that are not 200 #8532
+ * Update the SSL context after accepting incoming connections #8515
+ * Allow to create API User with password #8321
+ * Send Content-Type as API response header too #8108
+ * Display a correct status when removing a downtime #8104
+ * Display log message if a permission error occurs #8087
+ * Replace broken package name validation regex #8825 #8946
+* Windows
+ * Fix Windows command escape for \" #7092
+* Notifications/Downtimes
+ * Fix no re-notification for non OK state changes with time delay #8562
+ * TimePeriod/ScheduledDowntime: Improve DST handling #8921
+ * Don't send notifications while suppressed by checkable #8513
+ * Fix a crash while removing a downtime from a disappeared checkable #8229
+* IDO
+ * Update program status on stop #8730
+ * Also mark objects inactive in memory on object deactivation #8626
+ * IdoCheckTask: Don't override checkable critical with warn state #8613
+ * PostgreSQL: Do not set standard_conforming_strings to off #8123
+* ITL
+ * check_http: Fix assignment of check_adress blocking check by hostname #8109
+ * check_mysql: Don't set -H if -s is given #8020
+* Metrics
+ * OpenTSDB-Writer: Remove incorrect space causing missing tag error #8245
+
## 2.12.5 (2021-07-15)
Version 2.12.5 fixes two security vulnerabilities that may lead to privilege
diff --git a/ICINGA2_VERSION b/ICINGA2_VERSION
index ca6922f5c..207f0d364 100644
--- a/ICINGA2_VERSION
+++ b/ICINGA2_VERSION
@@ -1,2 +1,2 @@
-Version: 2.12.0
+Version: 2.13.0
Revision: 1
diff --git a/doc/16-upgrading-icinga-2.md b/doc/16-upgrading-icinga-2.md
index 4b0027399..b6a7d500c 100644
--- a/doc/16-upgrading-icinga-2.md
+++ b/doc/16-upgrading-icinga-2.md
@@ -8,6 +8,39 @@ Specific version upgrades are described below. Please note that version
updates are incremental. An upgrade from v2.6 to v2.8 requires to
follow the instructions for v2.7 too.
+## Upgrading to v2.13
+
+### DB IDO Schema Update
+
+There is an optional schema update on MySQL which increases the max length of object names from 128 to 255 characters.
+
+Please proceed here for the [MySQL upgrading docs](16-upgrading-icinga-2.md#upgrading-mysql-db).
+
+### Behavior changes
+
+#### Deletion of child downtimes on services
+
+Service downtimes created while using the `all_services` flag on the [schedule-downtime](12-icinga2-api.md#schedule-downtime) API action
+will now automatically be deleted when deleting the hosts downtime.
+
+#### Windows Event Log
+
+Icinga 2.13 now supports logging to the Windows Event Log. Icinga will now also log messages from the early
+startup phase to the Windows Event Log. These were previously missing from the log file and you could only
+see them by manually starting Icinga in the foreground.
+
+This feature is now enabled and replaces the existing mainlog feature logging to a file. When upgrading, the installer
+will enable the windowseventlog feature and disable the mainlog feature. Logging to a file is still possible.
+If you don't want this configuration migration on upgrade, you can opt-out by installing
+the `%ProgramData%\icinga2\etc\icinga2\features-available\windowseventlog.conf` file before upgrading to Icinga 2.13.
+
+#### Broken API package name validation
+
+This version has replaced a broken regex in the API package validation code which results in package names
+now being validated correctly. Package names should now only consist of alphanumeric characters, dashes and underscores.
+
+This change only applies to newly created packages to support already existing ones.
+
## Upgrading to v2.12
* CLI