Christopher Columbus (ca 1446 - 1506), Italian explorer who believed that the Earth was round, and that trade routes with Asia could be established by sailing westward. In August 1492, with eighty-seven men and three ships, he setsail for the west and discovered the Western Hemisphere. He made three other voyages to the Western Hemisphere in 1493, 1498 and 1502. —State of ManCongress Approved Gls (14.5.92)