Amerigo Vespucci (1452-1512) was born in Florence, where he worked for the commercial house of the Medici family as a young man. Perhaps he studied astronomy at this time. Sometime between 1489 and 1491 he moved to Barcelona as a confidential agent of the Medici.

He met Christopher Columbus shortly after the 1492 voyage, and Vespucci helped to finance the equipping of the ships for the second expedition. The two were friends: Columbus, in a letter to his son in 1505, speaks favorably about Vespucci, as a witness for his will.

Apparently (though this is debated) Vespucci made four voyages. He said he sailed with the Spanish to Venezuela and Haiti in 1497-8 and to Cape Verde, Venezuela, and Brazil in 1499-1500, and then with the Portuguese to Brazil and Patagonia in 1501-2 and to Brazil again in 1503-4.

The well-traveled Vespucci returned to Seville in 1505, received Spanish citizenship, and three years later was appointed as the "Pilot Major" for the Casa de Contratación. His responsibilities included teaching navigators who were sailing the ships that Spain was sending on long voyages and drawing maps of newly discovered lands and updating them as needed.

Vespucci had planned to continue working on his travel accounts and accompanying maps. Indeed, in the Mundus Novus he writes that "I have resolved, Magnificent Lorenzo, that, just as I have given you an account by letter of what happened to me, I shall send you two depictions of the world, made and ordered by my own hand and knowledge: one will be a flat rendering and the other a map of the world in spherical form. . . ." (Vespucci 1992, 17).