In 1533, Suleiman the Magnificent ordered Hayreddin Barbarossa, whom he had summoned from Algiers, to build a large war fleet in the arsenal of Constantinople. Altogether 70 galleys were built during the winter of 1533–1534, manned by slave oarsmen, including 2,000 Jewish ones. With this fleet, Barbarossa conducted aggressive raids along the coast of Italy, until he conquered Tunis on 16 August 1534, ousting the local ruler, theretofore subservient to the Spanish, Muley Hasan. Barbarossa thus established a strong naval base in Tunis, which could be used for raids in the region, and on nearby Malta.