Prince Henry was successful in exploring a large piece of the African coastline. What were the effects, both positive and negative, of Prince Henry's interactions in Africa?

A positive effect is Portugal's successes in global exploration spurred others, including Christopher Columbus, to look for another sea route to Asia. Another positive is the Portuguese seized ports around the Indian Ocean, creating a vast trading empire. A negative effect was with slave tradings.The slave trade had major effects on African states. Because of the loss of countless numbers of young Africans, some small states disappeared forever. At the same time, new states arose, with ways of life that depended on the slave trade.