Led by Antonio de Vea, a Spanish naval expedition departed El Callao, Peru, for the fjords and channels of Patagonia to find whether rival colonial powers were in the region.

Antonio de Vea was a 17th-century Spanish sailor best known for leading the Antonio de Vea expedition to the fjords and channels of Patagonia in 1675–1676. The map of the archipelagoes of southern Chile made by Antonio de Vea was a milestone in local cartography. As far as it is known no new Spanish maps were made of the west coast of Patagonia until José de Moraleda y Montero's explorations in the late 18th century.

The Antonio de Vea expedition of 1675–1676 was a Spanish naval expedition to the fjords and channels of Patagonia aimed to find whether rival colonial powers—specifically, the English—were active in the region. While this was not the first Spanish expedition to the region, it was the largest up to then, involving 256 men, one ocean-going ship, two long boats and nine dalcas. The expedition dispelled suspicion about English bases in Patagonia. Spanish authorities' knowledge of western Patagonia was greatly improved by the expedition, yet Spanish interest in the area waned thereafter until the 1740s.

Callao is a Peruvian seaside city and region on the Pacific Ocean in the Lima metropolitan area. Callao is Peru's chief seaport and home to its main airport, Jorge Chávez International Airport. Callao municipality consists of the whole Callao region, which is also coterminous with the province of Callao. Founded in 1537 by the Spaniards, the city has a long naval history as one of the main ports in Latin America and the Pacific, as it was one of vital Spanish towns during the colonial era. Central Callao is about 15 km (9.3 mi) west of the Historic Center of Lima.

The southern coast of Chile presents a large number of fjords and fjord-like channels from the latitudes of Cape Horn to Reloncaví Estuary. Some fjords and channels are important navigable channels providing access to ports like Punta Arenas, Puerto Chacabuco, and Puerto Natales.