In 1534 also, Hasan Agha continued to be left in command of Algiers when Barbarossa waged his campaigns in Tunisia. Hasan Agha ruled Algiers until 1545, as Barbarossa continued to be based in Istanbul as Commander-in-Chief of the Ottoman fleet. Hasan Agha was the commander of Algiers during the Algiers expedition (1541), in which Barbarossa was absent, and which ended with catastrophic results for Charles V. In 1542, he massacred the tribe of the Zaouaoua, who had supplied Charles V with 2,000 troops.