Christopher Columbus developed his proposal for reaching Asia by sailing west within the maritime world of the Mediterranean and Atlantic. He sought royal sponsorship after experience in Portuguese trading networks, but underestimated the distance across the ocean. The plan depended on mistaken geographical calculations, not on proving that the Earth was round, a view already accepted by educated contemporaries. After prolonged negotiation Ferdinand and Isabella supported an expedition in 1492, granting titles and prospective privileges tied to the lands and trade he expected to reach.

His fleet left Spain in August and made landfall in the Bahamas in October 1492, encountering Indigenous communities rather than an empty or unknown human world. He explored parts of Cuba and Hispaniola and returned with reports intended to secure support. A much larger second expedition in 1493 established a colonial settlement and imposed demands for labour, gold and submission. Violence, enslavement and disruption of Indigenous life were central to the enterprise. Columbus governed amid resistance from Taíno communities, disputes among colonists and expectations from the Spanish crown that the venture should yield wealth.

A third voyage in 1498 brought him to Trinidad and the South American coast, expanding his observations without persuading him that he had reached a separate continent. Complaints about government on Hispaniola led royal commissioner Francisco de Bobadilla to arrest him in 1500 and send him to Spain in chains. The monarchs released him but did not restore his former governing authority. A fourth voyage from 1502 to 1504 explored Central American coasts in search of a passage, bringing hardship, shipwreck and an extended stay in Jamaica before rescue. His navigational persistence coexisted with major failures of administration and interpretation.

In his final years Columbus pressed claims to revenues and privileges and sought to frame his achievements for royal patrons. He died in Valladolid in 1506, still understanding the voyages in relation to Asia. The crossings initiated sustained European colonization of the Americas, but later celebrations often obscured the peoples already living there and the coercive character of the first colonies. His surviving writings are valuable evidence of intentions and perceptions, while also serving claims of authority and reward. Conquest, disease and forced labour reshaped Atlantic societies beyond his own purposes.