 When Ali Pasha revolted against the Sublime Porte, Omer was his treasurer.He initially commanded the army tasked with defending the eastern approaches to Ioannina, but entered into an agreement with Ismail Pasha, the then commander-in-chief of the Sultan's forces, disbanding his army in exchange for the pashalik of Berat.After the death of Ali Pasha Omer was among the commanders who were sent by Hurşid Ahmed Pasha, the new commander-in-chief, to suppress the Greek Revolution which had broken out in March 1821.