Christopher Columbus (1451-1506), one of the most eminent Italian navigators, was born in Genoa in 1451. Having acquired considerable seafaring experience from his youth, he became convinced that the shortest route to the Indies was the westward one. The idea developed after his move to Lisbon around 1480. His brother Bartholomew was working there as a cartographer, and Columbus learned of the letter and map of Paolo dal Pozzo Toscanelli (1397-1482) setting out the hypothesis of a shorter route than the circumnavigation of Africa. Columbus submitted his plan to King John II of Portugal (1455-1495) in 1483, without success. He then went to Castile in search of a more positive reception, but he did not obtain the consent of the Spanish monarchs until spring 1492. Three ships were outfitted—two caravels and a carack—which set sail from Palos de la Frontera on August 3, 1492. This first voyage, which secured fame and fortune for Columbus, was followed by three others that, by contrast, drove him to failure and ruin. The Genoese admiral died in Valladolid on May 20, 1506.