The Peñón of Algiers, an islet in front of Algiers harbour had been occupied by the Spaniards as early as 1302. Thereafter, a considerable amount of trade began to flow between Algiers and Spain. However, Algiers continued to be of comparatively little importance until after the expulsion of the Moors from Spain, many of whom sought asylum in the city. In 1510, following their occupation of Oran and other towns on the coast of Africa, the Spaniards fortified the islet of Peñon and imposed a levy intended to suppress corsair activity.