Andrés de Urdaneta (1508[1]  – June 3, 1568) was a maritime explorer for the Spanish Empire of Basque heritage, who became an Augustinian friar.

[5][6] When he was seventeen, Urdaneta was invited to join the Loaísa expedition, serving as a page to Juan Sebastián Elcano, the Basque mariner who had recently captained the first ship to circumnavigate the globe.

[5] Urdaneta and the dwindling remnants of the expedition remained in the Spice Islands for more than eight years, fighting a losing effort against the Portuguese to maintain a presence in the region.

From Java he traveled to Malacca and then Cochin where he boarded a Portuguese spice ship, the Sao Roque, and returned to Europe.

[5] When he arrived in Valladolid, Urdaneta was interviewed by the Council of the Indies and wrote an extensive report detailing the events of the expedition and adding information regarding regional geography, trade, history and anthropology.

He was assembling a fleet of vessels on the Pacific coast of New Spain and invited Urdaneta to serve as chief navigator.

In transit, he stopped at Hispaniola where he related the story of the Loaísa expedition to historian Gonzalo Fernández de Oviedo.

[5][7] By June, 1540, the Alvarado expedition was ready to sail for Asia when word arrived from Cristóbal de Oñate that a serious native rebellion in New Galicia threatened to overwhelm Spanish control of the region.

In the same year Urdaneta was appointed visitador (auditor), an important office that reported directly to the viceroy and was responsible for investigating official corruption, mistreatment of the natives, or other misdeeds.

In 1543, when the survivors of the Cabrillo expedition returned from California, Urdaneta interviewed them about the journey and wrote what became the only surviving manuscript account of the voyage.

[5] Urdaneta's career took a surprising turn in 1552 when he set aside his secular life and joined the Augustinians, a Catholic religious order that observed a strict vow of poverty and focused on education and missionary work.

[5] In 1558, Viceroy Luís de Velasco wrote to Philip II and suggested that an expedition should be sent from Mexico to "the Islands of the West" (the Philippines).

Velasco further suggested that Urdaneta would be the ideal leader of the initiative because of his previous experience in the region and his knowledge of navigation, geography, and native languages.

Based on Urdaneta's recommendation, the viceroy appointed Miguel López de Legazpi to command the initiative.

Urdaneta would participate as an advisor and lead a small group of Augustine missionaries to establish the Catholic Church and evangelize the Pacific islanders.

The ships' pilots consistently overestimated their progress and derided Urdaneta when he (correctly) argued that the fleet was far short of where they estimated.

Finally, Legazpi established a fortified settlement on Cebu, where food was plentiful and a commercial center for trade with China was already in place.

As planned, Urdaneta was the chief advisor and Legazpi's seventeen-year-old grandson, Felipe de Salcedo, was named commander of the San Pedro, their largest ship and the one in best condition to face the difficult trip home.

Per Urdaneta's recommendation, they left Cebu on 1 June 1565, an ideal time to catch the south-west monsoon winds but avoid the typhoons that occurred later in the season.

After reaching clear water, the San Pedro sailed northeast to the 38th parallel where the ship encountered favorable westerly winds that carried them across the Pacific.

Urdaneta was ultimately recognized as the pioneer of the return route, based on his detailed notes and his solid reputation as a geographer and navigator.

Urdaneta stopped at Havana and gave an account of his voyage to Pedro Menéndez de Avilés before reaching Spain in April 1566.

In Seville, he gave his account to the Casa de Contratación and then proceeded to Madrid where he shared his experiences and observations with Philip II at the royal court.