The conflict was initiated when the Moroccan ruler Mohammed ash-Sheikh refused to give allegiance to the Ottomans. The Moroccan ruler had formed an alliance with the Spanish against the Ottomans. Hasan Pasha, the son of Barbarossa, was named by the Ottoman Empire beylerbey of the Regency of Algiers in June 1557, in order to continue the fight against the Moroccan ruler. He had Mohammed ash-Sheikh assassinated in October 1557 by one of his body guards.