The Siege of Oran of 1556 occurred when Ottoman troops from Algiers besieged the Spanish garrison in Oran. The siege, by land and sea, was unsuccessful and had to be lifted in August 1556 when the Ottoman fleet of 40 galleys was recalled for duty in the East Mediterranean. During the time the Ottomans were occupied in the siege, the Moroccans, who were allied with the Spanish, occupied the city of Tlemcen.