ulf of Mexico in an attempt to reach Panuco, Mexico. Cabeza de Vaca and a small group of survivors were separated from Narvaez and eventually landed on what is now Galveston Island, Texas. The small band of survivors were captured by natives and the rest of Cabeza de Vaca's Relacion recounts how he and three other survivors (Andres Dorantes, Alonso Castillo, and Estebanico) began a journey across the Southwestern United States and northern Mexico.
 In 1536, after a journey of eight years of contact with a variety of native people including the Karankawas, Caddoes, Atakapan, Jumano, Concho, Pimas, Mariames, and Avavares tribes, the survivors encountered the Spanish settlement of San Miguel De Culican on the Sinalo River in Mexico. During his journey, Cabeza de Vaca in Relacion reports that he lived as a slave, a trader, and a shaman among the native peoples. Relacion, written to the Spanish crown, contains an appeal for tolerant treatment of the native peoples. Cabeza de Vaca, Dorantes, and Castillo journeyed to Mexico-Tenochtitlan and reported the fate of the Narvaez expedition in a dispatch to the Emperor and the Audiencia in Santo Domingo. Cabeza de Vaca returned to Spain in the autumn of 1537.
 The account of the failure of the Narvaez expedition and the travels of the four survivors is detailed in Cabeza de Vaca's 1542 Relacion and a now lost document known as the Joint Report, a thirty page summary of the failed expedition written by Cabeza de Vaca, Dorantes, and Castillo in 1536 in Mexico-Tenochtitlan. A version of the lost Joint Report can be found in a work by Gonzalo Fernandez de Oviedo y Valdes written in 1539. Cabeza de Vaca wrote his account in Castile between 1537 and 1540.
 When Cabeza de Vaca returned to Spain in 1537 following his experiences in North America, he attempted to secure a royal commission from Emperor Charles V to command an expedition to Florida. He went to the royal court at Vallodolid between November 8 and December 24, 1537, to present his credentials in hope of securing the commission. The emperor, however, had already commissioned Hernando de Soto on April 20,1537, to lead the expedition in conquest of Florida.
 On March 18, 1540 the emperor awarded Cabeza de Vaca the title of Adelantado (a title awarded to conquerors and discoverers) and a royal contract for the governorship of Rio de la Plata, a region in South America that stretches from Peru to the Straits of Magellan and includes modern- day Paraguay. Cabeza de Vaca accepted the commission and set sail for Rio de la Plata from Cadiz on December 2, 1540, with four ships and four hundred men. After a five-month sea journey, Cabeza de Vaca's expeditionary force landed at the island of Santa Catalina, Brazil on March 29, 1541. After an eight-month stay in Brazil, Cabeza de Vaca led the expedition on an overland one thousand mile march to Paraguay. Along the way, Cabeza de Vaca was the first European to see the Igauzu Falls. The expedition arrived in Asuncion on March 11, 1542, and Cabeza de Vaca took command of Rio de la Plata, replacing the interim governor Martinez de Irala.
 Cabeza de Vaca's term as adelantado of Rio de la Plata was marked by a series of progressive reforms for the treatment of natives and for handling conflict with other Spanish officials. Rolena Adorno and Patrick Pautz in their history of Cabeza de Vaca's life note that "the title of adelantado gave Cabeza de Vaca supreme powers as judicial and military ruler " in Rio de Plata, but the title "meant little to conquistadors and soldiers already established in the area who jealously guarded the prerogatives they had claimed for themselves" (Vol.1, 387-88). Most historians report that the colonists of Rio de la Plata and former governor Irala were at odds with Cabeza de Vaca over his reform policies towards the treatment of the natives. On April 8, 1544, Cabeza de Vaca returned to Asuncion from an unsuccessful expedition seeking the mythical city El Dorado and found himself faced with a revolt of the colonists led by Irala. Cabeza de Vaca was arrested on April 25, 15