Juan de Salazar de Espinosa was a Spanish soldier, born in Villa Pomar in the end of the 15th century and died in Asuncion in 1566.

Salazar sailed in the expedition of Pedro de Mendoza and aided in the foundation of Buenos Ayres. Mendoza sent two sailors in the search of a shorter route to Peru, Domingo Martinez de Irala, and Ayolas. They sailed until they got to a bay in the Paraguay River, and Ayolas left Irala as he continued on his search to the Sierra de la Plata. Ayolas managed to get all the way to Peru, but he never came back and people thought he was dead. When Mendoza heard the news, he sent Juan Salazar de Espinosa and Gonzalo de Mendoza to look for Ayolas. At the same time they met Domingo Martinez de Irala, which was also looking for Ayolas, and since they had no news of Ayolas they decided to go back and it was then that Salazar founded the Fuerte Nuestra Señora de la Asunción on the eastern side of the Paraguay River, on august 15 of 1537. Dr. Chaves states that “the act of this foundation couldn’t have been simpler.” The small fort, a house made of wood, received the name “Nuestra Senora de la Asuncion for having been created on that day,” it was the feast day honoring the Assumption of the Virgin Mary.

In 1538, Salazar was designated as the first mayor in Asuncion; later on in 1542 he was appointed governor of Asuncion. In 1544, Salazar was successor of Cabeza de Vaca when he was taken captive by Irala. While Cabeza de Vaca was still a prisoner, Salazar was became treasurer of the provinces in La Plata by the royal council of Spain. When the governor died his son elected Salazar to be his substitute. In 1550, the expedition from San Lucar sailed by Hernando de Trejo, he depressed the privileges of Salazar and abandoned him in San Vicente, Brazil, where he stayed for two years and then went back to Asuncion, and took the position as Royal Treasurer and named Regime.

Salazar lived his last years in Asuncion, where he died on February 11, 1560, leaving the mestizo descent with Agustin, Hipolito and Juan de Salazar. He was buried at the feet of the mayor altar of the primitive Asunción Cathedral.