In 1402 Jean de Bethencourt, an adventurer from Normandy, discovered or rediscovered the Canaries and made himself master of the islands of Lanzarote, Fuerteventura, Gomera and Hierro. After various changes of ownership, they fell to the crown of Castile, and Isabella undertook the conquest of the remainder of the group, the Grand Canary, Tenerife and la Palma. The sturdy resistance of the native Guanches rendered the enterprise an arduous one, consuming eighteen years, and it was not until 1496 that it was finally accomplished. That Columbus, on his first voyage, took his departure from Gomera indicates the importance assumed by the Canaries in the development of trade with the New World and this, conjoined with their productiveness, as they became settled and cultivated, rendered them a centre of commerce frequented by the ships of all maritime nations, as well as an object of buccaneering raids, in an age when trade and piracy were sometimes indistinguishable. Their proximity to Morocco and the Guinea coast moreover exposed them to attacks from the Moors and gave them an opportunity of accumulating Moorish and negro slaves, whom the piety of the age sought to convert into Christians by the water of baptism. In various ways, therefore, there came to be abundant material for inquisitorial activity, although the Judaizing New Christians, who furnished the Spanish tribunals with their principal business, appear to have been singularly few.