In 1451, Prince Henry the Navigator helped fund and develop a new type of ship, the caravel, that featured triangular lateen sails and would be able to travel in the open ocean and sail against the wind. In 1488, Bartholomew Diaz rounded the southern tip of Africa, named the Cape of Good Hope by King John of Portugal, and entered the Indian Ocean from the Atlantic.
One explorer, Christopher Columbus, sought funding from the Portuguese to search for a passage to Asia by sailing westwards, but he was rejected. At this time in the late 15th century, Portugal’s domination of the western African sea routes prompted the neighboring Crown of Castile and the Catholic monarchs in modern Spain to search for an alternative route to south and east Asia (termed Indies), so they provided Columbus with the funding he required. By the time Christopher Columbus started setting back east from the New World after landing there in October 1492, he had explored San Salvador in the Bahamas (which he thought was Japan), Cuba (which he thought was China), and Hispaniola, the source of gold. As the common story goes, Columbus, en route back to Spain from his first journey, called in at Lisbon as a courtesy to brief the Portuguese King John II of his discovery of the New World. King John subsequently protested that according to the 1479 Treaty of Alcáçovas, which divided the Atlantic Ocean between Spanish and Portuguese spheres of influence, the newly discovered lands rightly belonged to Portugal. To make clear the point, a Portuguese fleet was authorized and dispatched west from the Tagus to lay claim to the “Indies,” which prompted a flurry of diplomatic activity in the court of Ferdinand and Isabella.
