Columbus and the Encounter with the Americas

Christopher Columbus (in Spanish, Cristóbal Colón), a Genoese mariner, proposed reaching Asia by sailing west across the Atlantic, a plan resting on a significant underestimate of the Earth's circumference (he used a figure closer to Ptolemy's smaller estimate rather than the more accurate one calculated by Eratosthenes in the 3rd century BCE). After Portugal's royal advisors rejected his proposal as impractical, Columbus secured backing from Ferdinand and Isabella of Spain through the 1492 Capitulaciones de Santa Fe, which promised him noble titles, a share of future revenues, and governorship over any territories discovered.