 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.Isabella and Ferdinand authorized the 1492 expedition of Christopher Columbus, who became the first known European to reach the New World since Leif Ericson.This and subsequent expeditions led to an influx of wealth into Spain, supplementing income from within Castile for the state that would prove to be a dominant power of Europe for the next two centuries.