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.

[2] With this fleet, Barbarossa conducted aggressive raids along the coast of Italy, until he landed in Tunis on 16 August 1534, ousting the local ruler, theretofore subservient to the Spanish, the Hafsid Regent Muley Hasan.

[3] Barbarossa thus established a strong naval base in Tunis, which could be used for raids in the region, and on nearby Malta.

[4] Tunis was a highly strategic location, controlling the passage from the west to the eastern basin of the Mediterranean.

In 1535 however, upon the plea of Muley Hasan, Emperor Charles V mounted a counter-offensive and retook the city in the conquest of Tunis of 1535.