Portugal's neighbouring fellow Iberian rival, Castile, had begun to establish its rule over the Canary Islands, located off the west African coast, in 1402, but then became distracted by internal Iberian politics and the repelling of Islamic invasion attempts and raids through most of the 15th century. Only late in the century, following the unification of the crowns of Castile and Aragon and the completion of the reconquista, did an emerging modern Spain become fully committed to the search for new trade routes overseas. The Crown of Aragon had been an important maritime potentate in the Mediterranean, controlling territories in eastern Spain, southwestern France, major islands like Sicily, Malta, and the Kingdom of Naples and Sardinia, with mainland possessions as far as Greece. In 1492 the joint rulers conquered the Moorish kingdom of Granada, which had been providing Castile with African goods through tribute, and decided to fund Christopher Columbus' expedition in the hope of bypassing Portugal's monopoly on west African sea routes, to reach "the Indies" (east and south Asia) by travelling west. Twice before, in 1485 and 1488, Columbus had presented the project to king John II of Portugal, who rejected it.
On the evening of 3 August 1492, Columbus departed from Palos de la Frontera with three ships; one larger carrack, Santa María, nicknamed Gallega (the Galician), and two smaller caravels, Pinta (the Painted) and Santa Clara, nicknamed Niña. Columbus first sailed to the Canary Islands, where he restocked for what turned out to be a five-week voyage across the ocean, crossing a section of the Atlantic that became known as the Sargasso Sea.
Land was sighted on 12 October 1492, and Columbus called the island (now The Bahamas) San Salvador, in what he thought to be the "West Indies". Columbus also explored the northeast coast of Cuba (landed on 28 October) and the northern coast of Hispaniola, by 5 December. He was received by the native cacique Guacanagari, who gave him permission to leave some of his men behind.
Columbus left 39 men and founded the settlement of La Navidad in what is now present-day Haiti. Before returning to Spain, he kidnapped some ten to twenty-five natives and took them back with him. Only seven or eight of the native Indians arrived in Spain alive, but they made quite an impression on Seville.
Columbus and other Spanish explorers were initially disappointed with their discoveries—unlike Africa or Asia the Caribbean islanders had little to trade with the Spanish ships. The islands thus became the focus of colonization efforts. It was not until the continent itself was explored that Spain found the wealth it had sought.