In one of the most improbably successful voyages in known history, Orellana managed to sail the length of the Amazon, arriving at the river's mouth on 24 August 1542.

Born in Trujillo in western Spain (various birth dates, ranging from 1490 to 1511, are still quoted by biographers), Orellana was a close friend and possibly a relative of Francisco Pizarro, the Trujillo-born conquistador of Peru (his cousin, according to some historians).

On reaching the Coca River (a tributary of the Napo), a brigantine, the San Pedro, was constructed to ferry the sick and supplies.

Orellana (with the Dominican Gaspar de Carvajal who chronicled the expedition) and 50 men set off downstream to find food.

Unable to return against the current, Orellana waited for Pizarro, finally sending back three men with a message, and started constructing a second brigantine, the Victoria.

The Victoria, carrying Orellana and Carvajal, passed south around Trinidad and was trapped in the Gulf of Paria for seven days, finally reaching Cubagua on 11 September 1542.

From Cubagua, Orellana decided to return to Spain to obtain from the Crown the governorship over the discovered lands, which he named New Andalusia.

[3] After captivating the Spanish court with tales and alleged exaggerations of his voyage down the Amazon, Orellana obtained a commission to conquer and settle Nueva Andalucia.

The charter established that he should explore and settle the Amazonian lands with 300 men and 100 horses, and found two cities, one in the mouth and another in the basin's interior, Manaus.

However, the problems were compounded by Orellana's decision to marry a very young and poor girl, Ana de Ayala, whom he intended to take with him (along with her sisters).

On reaching Sanlucar he was detained again, the authorities having discovered a shortfall in his complement of men and horses, and that large numbers of his crew were not Spanish.

He reached the Brazil coast, sailed a hundred leagues until he found fresh water in the sea, which he assumed came from the Amazon.

The survivors went downriver to the sea where they were driven by the South Equatorial Current to the Spanish base at Margarita Island west of Trinidad.

After Orellana left the shipwreck camp, the 28 or 30 men there began building a boat from the wrecked ship, which took more than three months.

[10] The BBC documentary Unnatural Histories presents evidence that Carvajal's chronicle, rather than being a hugely exaggerated fantasy as previously thought, was correct in its observations that a civilization was flourishing along the Amazon in the 1540s.

[11] The evidence to support this claim comes from the discovery of numerous geoglyphs dating from between 1 and 1250 AD, and terra preta resulting from indigenous activities.

[13] A modern retelling of Orellana and his crew's epic journey, with source material primarily provided by Carvajal, is written in Buddy Levy's River of Darkness.

[14] De Orellana's voyages served as partial inspiration for the film Aguirre, the Wrath of God (1972).

An earlier script, penned by director Werner Herzog, also deliberately included De Orellana in the movie, but he was ultimately left out.

[citation needed] De Orellana's role in the search for El Dorado also forms part of the plot of the film Indiana Jones and the Kingdom of the Crystal Skull (2008).

[15] One of the campaigns of Age of Empires II: The Forgotten is called El Dorado and is about the quest of Francisco de Orellana and Francisco Pizarro to find El Dorado, the legendary Lost City of Gold, thought to be hidden somewhere in the vast Amazon rainforest.