Overview

During the 1440s, Nuño Tristão explored a large portion of Africa's west coast in a series of expeditions commissioned by Portugal's Prince Henry the Navigator. Tristão, one of Prince Henry's most trusted sea captains, is credited with the discovery of Cape Blanc, Arguin Island, and the Gambia River. Tristão was one of the first Europeans to engage in the slave trade, and under his command Arguin Island became the staging area for slaves bound for Portugal. This fertile period of exploration of Africa's western coast established Portugal as a leader in the emerging colonial world.

Background

In 1415 Portugal began its era of geographic discovery and the establishment of colonies. At the time it had a relatively stable monarchy whose kings encouraged maritime trade. Portugal's natural geographic position...