Felipe de Rábago y Terán, Spanish soldier, was likely born in New Spain during the third decade of the eighteenth century. A contemporary, Texas Governor Jacinto de Barrios y Jáuregui in remarking about Rábago's early life, noted that he had acquired a good deal of wealth from the mines of Zacatecas and that he possessed more money than judgment. Rábago first appears in the written record at the exact mid-point of the 1700s. On March 6, 1750, King Ferdinand VI designated him as commander of a proposed presidio in Central Texas, soon to be named San Francisco Xavier de Gigedo. En route to his post, which he reached in December 1751, Rábago, then a young man in his early thirties, scandalized the Franciscans in his party by engaging in licentious relations with Indian and Hispanic women, whether married or single.
After conducting a brief survey of three San Xavier missions in January 1752, Rábago urged their removal from the San Gabriel River near modern Rockdale, Texas, to a more favorable site on the San Marcos River, but the missionaries adamantly rejected his request. This disagreement, which forced Rábago to build the presidio where he did not wish it to be, as well as his salacious relationship with the wife of Juan José Ceballos, a tailor from San Antonio, prompted heated quarrels with the Franciscans. Those differences and other disputes between presidials and clerics led to the temporary excommunication of Rábago and the entire San Xavier garrison in late February 1752. On May 11, 1752, Ceballos and Father Juan José de Ganzabal were murdered at Nuestra Señora de la Candelaria Mission, and Rábago was suspiciously linked to their deaths. He was removed from command and sent to Presidio Santa Rosa del Sacramento in Monclova, where he languished for eight years while charges against him were investigated. Following the destruction of Santa Cruz de San Sabá Mission in 1758 and the subsequent removal of Diego Ortiz Parrilla as commander of San Luis de las Amarillas Presidio, Rábago, on June 7, 1760, was exonerated in the double murder case and selected as Parrilla's replacement. He reached the San Saba River on September 30, and took charge of the presidio on the following day. Among his most important accomplishments there was the replacement of the wooden presidio with an impressive rectangular fortress of mortar and stone, which he completed in late 1761.
During his long confinement at Monclova, Rábago appears to have experienced a remarkable transformation that has puzzled his most harsh critics. He demonstrated "a great change of heart" by committing himself to the conversion and missionizing of the Lipan Apaches. To this end he recruited Father Diego Jiménez, president of missions on the Rio Grande, to assist him in founding two new missions on the upper Nueces River in present-day Uvalde and Real Counties. Known collectively as the El Cañón missions, these religious outposts enjoyed modest success in the 1760s. At the same time, the presidio at San Sabá came under relentless attacks from Comanches, mortal enemies of the Lipan Apaches. To defend the garrison and the two missions, Rábago expended more than 12,000 pesos of his own money. In the spring of 1768, under almost constant threats by the Comanches, soldiers and their families dared not plant fresh vegetables and other crops beyond the presidio's protective walls. Limited in diet, the residents and Rábago himself suffered horribly from scurvy. In desperation, Rábago abandoned his post and relocated the garrison near one of the missions. When the viceroy learned of the unauthorized move, he ordered Rábago back to San Sabá, but Rábago refused to comply. Leaving the upper Nueces, he traveled to Coahuila seeking supplies for his troops and the mission residents. There in April 1769 he learned of his replacement at San Sabá by Manuel Antonio de Oca y Alemán. From Coahuila, Rábago set out for Mexico City, where he hoped to obtain recompense for expenditures of his own monies. But he never completed the trip. He died at San Luis Potosí, probably in July of 1769.