Christopher Columbus
In February 1495, Columbus started the transatlantic slave trade.  He and his soldiers captured about 1,500 Taíno.  Only 500 could fit on Columbus's ships, so Columbus told his men they could take any of the rest as slaves.  They took 600 and let 400 go.  Of the 500 natives that Columbus shipped to Spain as slaves, about 200 died on the trip.  Half of the rest were very sick when they arrived.  This was the first time people had ever been shipped across the Atlantic Ocean to be sold as slaves.