Here is the full list of all 11 Manor Lords achievements.
Reach 100% approval in a "large town".
Get to a "small town" settlement level without hunting or gathering berries.
Beat "Restoring the peace" with Mercenary units only.
Beat "Restoring the peace" on "Challenging" difficulty preset.
Finish the "Restoring the peace" scenario
Defeat the baron in the "Restoring the peace" scenario.
Employ 24 retainers.
Change the church bell sound.
Destroy a squad of brigands with a squad of militia in a non battle game mode.
Face the winter and have your settlers not abandon you.
Big success!