Manuel Muñoz was probably born in Matamoros, Castile, Spain around 1730. He was a captain in the Spanish army when he arrived in Texas as commander of the newly established Presidio del Norte in December 1759. The following year he helped repulse an attack by Apache Indians, and he served at the post for many years. He commanded the Nueva Vizcaya contingent during Col. Hugo Oconór's Indian campaign of 1775. Muñoz was promoted to lieutenant colonel in 1777, and eventually to colonel. In the 1770s and 1780s he served at a number of posts along the Rio Grande, negotiated with the Mescalero Apaches, and conducted campaigns against border renegades. Muñoz succeeded Rafael Martínez Pacheco as governor of Texas in 1790. Two years later the Conde de Sierra visited to investigate his administration and while he was doing so served as acting governor. In 1793 Muñoz carried out the decree of secularization for San Antonio de Valero Mission and the following year a decree of "partial secularization" for the other four San Antonio missions (see SPANISH MISSIONS). He made the Christian Indians at these missions independent landowners, restricted the missionaries to the sacred ministry, and placed the common property of the mission Indians under the supervision of Spanish justice or the alcalde. But Zacatecan missionaries continued to serve the four missions for three more decades, until their final secularization in 1824. A new mission, Refugio, was founded in 1793. Muñoz became sick in 1796 and requested permission to retire. Juan Bautista Elguézabal was appointed to assist Muñoz until an answer could be obtained from the king. In January 1797 Muñoz was informed that Manuel Antonio Cordero y Bustamante, governor of Coahuila, had been appointed his successor; but Cordero was then engaged in a campaign against the Apaches, and Muñoz was asked to remain in office until further notice. In March of the same year Cordero sent word that he could not come to Texas because he had become lieutenant governor of Nuevo Santander. A half year later José Irigoyen was named governor of Texas, but illness prevented him from assuming his duties and Elguézabal was made interim governor. Muñoz died in San Antonio on July 27, 1799, and Elguézabal succeeded him. María Gertrudis del Cipiran, Muñoz's wife and a fellow native of Castile, had apparently preceded him in death some five years earlier.