Until the late thirteenth century, European maritime commerce had been divided between a Mediterranean and a North Atlantic world. Starting around 1270, however, Italian merchants began to sail through the Strait of Gibraltar and on to the wool- producing regions of England and the Netherlands. This was the essential first step in the extension of Mediterranean commerce and colonization into the Atlantic Ocean. The second step was the discovery by Genoese sailors, during the fourteenth century, of the Atlantic island chains known as the Canaries and the Azores. Efforts to colonize the Canary Islands and to convert and enslave their inhabitants began almost immediately. But an effective conquest of the Canary Islands did not begin until the fifteenth century, when it was undertaken by Portugal and completed by Spain. The Canaries, in turn, became the base from which further Portuguese voyages down the west coast of Africa proceeded. They were also the “jumping-off point” from which Christopher Columbus would sail westward across the Atlantic Ocean in hopes of reaching Asia.