<P> In 1402, the Castilian conquest of the islands began, with the expedition of French explorers Jean de Béthencourt and Gadifer de la Salle, nobles and vassals of Henry III of Castile, to Lanzarote . From there, they conquered Fuerteventura (1405) and El Hierro . Béthencourt received the title King of the Canary Islands, but still recognised King Henry III as his overlord . It was not a simple military enterprise, given the aboriginal resistance on some islands . Neither was it politically, since the particular interests of the nobility (determined to strengthen their economic and political power through the acquisition of the islands) and the states, particularly Castilla, in the midst of territorial expansion and in a process of strengthening of the Crown against the nobility . </P> <P> For their study, historians distinguish two periods in the conquest of the Canary Islands: </P> <P> Stately conquest It is known by this name to the conquest carried out by the nobility, for their own benefit and without direct participation of the Crown, which grants the right of conquest in exchange for a pact of vassalage of the noble conqueror to the Crown . We will distinguish within it the one known as Conquest Betancuriana or Normandy, carried out by Jean de Bethencourt and Gadifer de la Salle between 1402 and 1405 and that affected the islands of Lanzarote, El Hierro and Fuerteventura . The other phase is known as Castilian Conquest, carried out by Castilian nobles who appropriated, through purchases, assignments and marriages, the first conquered islands and incorporated the island of La Gomera around 1450 . Real conquest . This term defines the conquest carried out directly by the Crown of Castile, during the reign of the Catholic Monarchs who armed and partly financed the conquest of the islands that were still to be dominated: Gran Canaria, La Palma and Tenerife . In the year 1496, the conquest came to an end with the dominion of the island of Tenerife, integrating the Canary Archipelago in the Crown of Castile . The royal conquest took place between 1478 and 1496 . </P> <P> By 1520, European military technology combined with the devastating epidemics such as bubonic plague and pneumonia brought by the Castilians and enslavement and deportation of natives led to the extinction of the Guanches . </P>

When did the canary islands become spanish territory