The voyages of Christopher Columbus, who stumbled on the coast of America in 1492 when he was sailing westward to seek a passage to Asia on behalf of the Spanish court, stimulated the Portuguese to redouble their efforts to navigate around the Cape of Good Hope to Asia. In 1498 Vasco da Gama rounded the Cape of Good Hope and sailed up the east coast of Africa, crossing the Indian Ocean and reaching India in 1498. The Portuguese subsequently pushed further eastwards, reaching the Spice Islands (Moluccas) and China in 1513, and eventually reaching Japan in 1542. Wherever they went they established trading relations and new commercial opportunities opened up. Meanwhile, in the west, Columbus died in 1504, convinced that the Caribbean Islands he had reached were in fact Asia. The Spanish were quick to explore the interior of the new continent, penetrating into Central America and as far south as Peru, while the Portuguese explored eastern South America from 1500. In 1519 Ferdinand Magellan, a former Portuguese explorer now working for Charles V of Spain, sailed down the east coast of South America, rounded the southern tip of the continent and reached the Pacific Ocean. Only 18 of the original 280 crewmen made it back to Spain in 1522; it was the first circumnavigation of the earth.