When natives on the neighboring island of Gomera revolted, he brutally put down the rebellion, killing males over the age of fifteen and selling the women and children into slavery.

Cabeza de Vaca would have heard of these exploits growing up; many years later he named a province in South America, Vera, in honor of his grandfather.

His younger siblings went to live with their aunt but Álvar had already entered the service of Juan Alfonso Pérez de Guzmán, 3rd Duke of Medina Sidonia in 1503.

[10] The house of Medina Sidonia was one of the most powerful in Andalusia and was a dominant force in Seville, the commercial center of Spain's growing overseas empire.

When the Revolt of the Comuneros broke out in 1520 against the new Spanish king, Charles V, Cabeza de Vaca fought alongside the duke on behalf of the crown.

Cabeza de Vaca was named treasurer by royal appointment, a position that put him second in command and made him chiefly responsible to look after the emperor's interests during the expedition.

Their fleet of five vessels set sail from Spain on 17 June 1527, carrying 600 soldiers and colonists, including a few married women and African slaves.

In October, while Cabeza de Vaca was ashore negotiating for supplies, a hurricane hit the coast, resulting in the destruction of both ships and the loss of sixty men and twenty horses.

Communicating with them through sign language, the Spanish were informed that a community or region called Apalachee lay to the north and was rich with food and gold.

Cabeza de Vaca later noted that whenever Narváez expressed interest in something, the Indians assured him it could be found in great quantities at Apalachee.

He would lead some 300 men and 42 horses overland to Apalachee while the remaining crew, including the women, would sail ahead to find a suitable harbor and await their return.

Cabeza de Vaca pleaded with Narváez to send a scouting expedition downriver in hopes of finding a bay where their ships might be waiting.

Their guides assured them this was a major Apalachee settlement, so Narváez ordered Cabeza de Vaca to lead about fifty soldiers to seize the village.

Turning inland because of the threat of hostile Indians, he and his companions continued through Coahuila and Nueva Vizcaya (present-day states of Chihuahua and Durango); then down the Gulf of California coast to what is now Sinaloa, Mexico, over a period of roughly eight years.

Cabeza de Vaca was assigned to find a usable route from this colony to the riches of the former Incan Empire in Peru and Bolivia now controlled by the Spanish.

With an indigenous force, plus 250 musketeers and 26 horses, he followed native trails[32] discovered by Aleixo Garcia overland to the district's Spanish capital, Asunción, far inland on the great Paraguay River.

The government of Asunción pledged loyalty to Cabeza de Vaca, and Irala was assigned to explore a possible route to Peru.

He hoped to reach Los Reyes (a base that Irala set up) and push forward into the jungle in search of a route to the gold and silver mines of Peru.

[33] They wandered along the Texas coast as prisoners of the Han and Capoque American Indians for two years, while Cabeza de Vaca observed the people, picking up their ways of life and customs.

The narrative of Cabeza de Vaca is the “first European book devoted completely to North America.”[35] His detailed account describes the lives of numerous tribes of American Indians of the time.

Cabeza de Vaca showed compassion and respect for native peoples, which, together with the great detail he recorded, distinguishes his narrative from others of the period.

[35] Cabeza de Vaca reported on the customs and ways of American Indian life, aware of his status as an early European explorer.

He describes details of the culture of the Malhado people, the Capoque, and Han American Indians, such as their treatment of offspring, their wedding rites, and their main sources of food.

"[36] Cabeza de Vaca's greatest challenge as an ambassador came when he attempted to bring peace between the conquering Spanish army and the natives.

Not long afterward, Cabeza de Vaca encountered the chief alcalde (Spanish captain of the province), Melchor Díaz.

[36] Cabeza de Vaca wrote this narrative to Charles V to “transmit what I saw and heard in the nine years I wandered lost and miserable over many remote lands”.

[34] He wanted to convey “not merely a report of positions and distances, flora and fauna, but of the customs of the numerous indigenous people I talked with and dwelt among, as well as any other matters I could hear of or observe”.

[citation needed] Herrera (2011) classifies Cabeza de Vaca's La Relacion as the first major contribution to Chicano literature.

[5] Laila Lalami's novel, The Moor's Account (2014), is a fictional memoir of Estevanico, the Moroccan slave who survived the journey and accompanied Cabeza de Vaca through the Southwest.

Russell Persson's The Way of Florida (Little Island Press, 2017) is a highly stylized novelization of Cabeza de Vaca's Relación.