Thanks to its geostrategic position on the Strait of Gibraltar, the city of Ceuta was one of the major trading centers of the medieval Mediterranean. Under the Afazids it was one of the key strategic points on the straits, during a time when the region was fiercely contested between Christian and Muslim powers (Aragon, Castile, Genoa, Portugal, Grenada and the Marinids). On August 21 1415 the city was taken by Portugal, taking advantage of the deep crisis that beset Morocco at the end of the Marinid period. This conquest was not a simple historical event but a turning point in Moroccan history whose political and economic consequences continue to affect Morocco today. The first part of this study traces Ceuta's strategic and commercial importance through its trade with particular Mediterranean powers and various efforts by foreign powers to control it, efforts crowned by the Portuguese occupation of 1415. In the second part we examine the reasons behind the Portuguese conquest of the city.