Amerigo Vespucci (9 March 1454 - 22 February 1512) was an Italian explorer, navigator and cartographer, born and brought up by his uncle in the Republic of Florence, in what is now Italy. Vespucci worked for Lorenzo de Medici and his son, Giovanni. In 1492, he was sent to work at the Seville branch of the Medici bank.

At the invitation of King Manuel I of Portugal, Vespucci participated as an observer in several voyages that explored the east coast of South America between 1499 and 1502. Manuel's commander Pedro Alvares Cabral, on his way to the Cape of Good Hope and India in 1500, had discovered Brazil at latitude 16簞52'S. Portugal claimed this land by the Treaty of Tordesillas, and the king wished to know whether it was merely an island or part of the continent that Spanish explorers had encountered further north.

Vespucci, having already been to the Brazilian shoulder, seemed the person best qualified to go as an observer with the new expedition. Vespucci did not command at the start