Exploration
Christopher Columbus was a Genoese navigator and explorer in the employ of Isabella of Castile. Under the Portuguese flag in 1492 he sailed three ships to discover a trade route to asia. Instead he landed in the Americas. It was thought he was the first European to see America, but Norse explorers had visited the continent centuries earlier. His findings triggered a series of explorations by other Europeans. He made a total of four voyages. The cost was high among the native populations, many of which were wiped out completely. They had no immunities to common diseases of Europe. As many as five million native Americans died due to disease, starvation and war with Europeans.