Joaquín de Montserrat, Marqués de Cruillas, was born in Valencia, Spain, in 1700. After a distinguished military career that included campaigns in France, North Africa, Gibraltar, and Italy, he gained administrative experience as governor of Badajoz and as commandant general of Aragon. In late life he served from October 6, 1760, to August 25, 1766, as the forty-fourth viceroy of New Spain.
The Marqués de Cruillas replaced an interim viceroy who had served briefly as successor to the Marqués de las Amarillas. And it was his bad luck to govern during really difficult times. Cruillas reached Mexico City shortly after the San Sabá massacre (1758) and the failed punitive campaign (1759) of Diego Ortiz Parrilla. His tenure also witnessed Spain's shifting role from neutral observer to active combatant in the Seven Years' War, the transfer of Louisiana from France to Spain near the end of that war, the costly and dramatically increased militarization of Mexico, the outbreak of horrible smallpox epidemics that claimed nearly 100,000 lives in just Mexico City and Puebla, and the sweeping inspection of frontier outposts conducted by the Marqués de Rubí. It is little wonder that the policies of this overburdened administrator, especially as they affected Texas, have drawn criticism.
Cruillas no doubt erred in choosing Felipe de Rábago y Terán, only recently exonerated of crimes committed at the San Xavier missions, to replace Ortiz Parrilla as the commander of San Luis de las Amarillas Presidio. Cruillas charged Rábago with the task of missionizing the Lipan Apaches at or near the ruins of San Lorenzo de San Sabá Mission, and he stressed the importance of establishing new forts and missions to the northwest of San Sabá-thereby linking Texas more closely with New Mexico. Rábago allowed the Lipans to influence his decisions and approved two new missions on the upper Nueces River between San Sabá and San Juan Bautista. The new missions, San Lorenzo de la Santa Cruz and Nuestra Señora de la Candelaria del Cañón, were not approved by the viceroy, and they seriously weakened the defenses of the presidio at San Sabá, as a permanent detachment of soldiers had to be assigned to the missions, and the presidio itself had to share provisions with those beleaguered outposts.
Near the end of his tenure as viceroy, the Marqués de Cruillas was obliged to receive two unwelcome royal appointees. The Marqués de Rubí, commissioned separately in Spain by King Charles III, was to carry out an all-encompassing inspection of presidios on the northern frontier of New Spain; and José Bernardo de Gálvez Gallardo was to serve as visitor general of public finance. The Rubí report was a devastating commentary on the condition of Spain's frontier garrisons, while Gálvez's overarching powers exceeded those of the viceroy himself. When the Marqués de Cruillas objected to the latter, he was replaced with the more compliant Marqués de Croix. The former viceroy returned to Spain and died at Valencia in 1771.