Francisco Orellana, a Spanish adventurer, born in Trujillo early in the 10th century, died near Montalegro, Brazil, about 1550. He accompanied Francisco Pizarro to Peru in 1531, and took part in the conquest of that country. When in 1540 Gonzalo Pizarro set out to explore the regions cast of the Andes, Orellana was second in command of the expedition, which comprised about 350 Spaniards, 4,000 Indians, and 1,000 dogs for hunting down the natives. The river Napo was discovered after a tedious and perilous march, and Pizarro, despairing of returning by the route he had traversed, constructed a brigantine large enough to hold the weaker part of his company and his baggage, and gave the command of it to Orellana, with instructions to keep alongside of the army while it followed by land the course of the river. After several weeks passed in the descent through a dreary wilderness, their provisions were exhausted, and Pizarro, hearing of a populous and rich district several days' journey down the river at the point where the Napo flowed into a still greater stream, despatched Orellana and 50 soldiers in the brig-antine to the confluence of the waters, to procure supplies.

The brigantine in three days reached the Amazon, then for the first time navigated by a European vessel (1541). Orellana found the country a wilderness, and altogether unlike what had been represented. To return against the current was difficult, and he resolved to abandon his commander and sail down the great river to the sea. He boldly prosecuted the voyage for seven months, attacked by the warlike natives whenever he attempted to land, and often pursued by them for miles in canoes. He reached the ocean in August, 1541, and sailed to the island of Cubagua, and thence to Spain, where he told that he had passed through a country inhabited only by women, who were warriors and conquerors, and that he had received authentic information of the existence of an El Dorado where gold was so plentiful that houses were roofed with it. After a few years he obtained from the Spanish crown a commission to conquer and colonize El Dorado, and sailed with four ships and 400 men. He lost one ship and 150 men before he reached Teneriffe. Ascending the Amazon some distance, he landed to construct a brigantine; but his last vessel was wrecked, and he died of a fever.