 The possession of the Canary Islands was a point of contention between the two Crowns.Later on, the control of commerce with the territories of Guinea and Elmina, rich in gold and slaves, grew to a dispute of even greater importance.During the first half of the century, Castile staged the conquest of a few of the Canary Islands (Lanzarote, Fuerteventura, Hierro, and La Gomera) by feudal pacts, first with Norman knights and later with Castilian nobles.