Early Polynesian explorers reached nearly all Pacific islands by 1200 CE, followed by Asian navigation in Southeast Asia and the West Pacific. During the Middle Ages, Muslim traders linked the Middle East and East Africa to the Asian Pacific coasts, reaching southern China and much of the Malay Archipelago. Direct European contact with the Pacific began in 1512, with the Portuguese encountering its western edges, soon followed by the Spanish arriving from the American coast.

Andrés de Urdaneta was a maritime explorer for the Spanish Empire of Basque heritage, who became an Augustinian friar. At the age of seventeen, he formed part of the Loaísa expedition to the Spice Islands where he spent more than eight years. Around 1540 he settled in New Spain and became an Augustinian friar in 1552. At the request of Philip II he joined the Legazpi expedition for a return to the Philippines. In 1565, Urdaneta discovered and plotted an easterly route across the Pacific Ocean, from the Philippines to Acapulco in the Viceroyalty of New Spain. The route made it practical for Spain to colonize the Philippines and was used as the Manila galleon trade route for more than two hundred years.