Domingo Terán de los Ríos was appointed first governor of the Spanish province of Texas. On January 23, 1691, the Conde de Gálvez appointed him to oversee the administration of Coahuila, Texas, and adjacent regions. Terán had been in the Spanish service in Peru for twenty years, had come to Mexico in 1681 as a deputy of the consulado of Sevilla, had been captain of infantry in the castle of San Juan de Ulúa and in 1686 was made governor of Sonora and Sinaloa, where he was successful in quelling Indian disturbances. His instructions for his Texas venture were prepared by a Junta de Hacienda acting under suggestions by Damián Massanet, who was in charge of missionary activities. Terán was instructed to establish seven missions among the Tejas, to investigate rumors of foreign settlements on the coast, and to keep records of geography, natives, and products. On May 16, 1691, Terán's army departed from its base camp in Monclova and crossed the Rio Grande on May 28. Members of the expedition named the Texas rivers they crossed in their progress eastward until they reached the Colorado River and camped there. A failed attempt by a small group of the expedition to make contact with a joint maritime expedition at Matagorda Bay in July became a source of early differences between Terán and Massanet. Terán wished to remain encamped on the Colorado River until resupplied by sea, but Massanet prevailed in his insistence that further delays were unacceptable. When they reached San Francisco de los Tejas, the governor renamed the country Nuevo Reyno de la Montaña de Santander y Santillana. Still having no word of support by sea, Teran headed back to Matagorda Bay. At the site of LaSalle’s Colony, he met Gregorio de Salinas Varona, who brought him new orders for the exploration of the country; so Terán had to return to East Texas, which he explored as far as Caddo settlements on the Red River by December 1691. The expedition experienced a difficult march back to the missions in East Texas, where a bitter dispute with Massanet arose over Terán's seizure of mission animals to replace his depleted horse herd. Continuing on to Matagorda Bay, where he arrived on March 5, 1692, Terán was met by Juan Enríquez Barroto, who gave him instructions from the viceroy to explore the lower reaches of the Mississippi River. Terán left his men in Texas and embarked on his new mission, but bad weather caused him to abandon the project and return to Veracruz on April 15. Terán's mission proved to be a complete failure. He succeeded in founding no new missions, and the expedition added little new information about the region. After his return, Terán compiled a lengthy report, defending his actions and detailing the dismal situation in East Texas.