He was born circa 1707, and was baptized 6 Apr 1707 in Monclova. His father was Joseph Antonio Ecay Muzquiz, and his mother was Francisca Javiera Flores de Valdez. Birth source: link
He married Mariana de la Garza Falcon, daughter of Gov. Gen Blas de la Garza Falcon and Beatriz de Villarreal on 20 Feb 1735 in Monclova. He was 28 years old, and the bride was 18 years old. Their padrino was Jose Joaquin de Urrutia y Ecay Muzquiz, and their madrina was Maria Candelaria de la Garza Falcon. Witnesses were Pedro Garcia de Rivera and Ignacio Guerra. The groom was absent and was married by proxy by Capitan don Miguel de la Garza, on 30 Oct 1734. Marriage source: link.
Juana Antonia Martina Ecay Muzquiz, baptized 22 Nov 1735 in Monclova. Her padrino was Blas de la Garza, and her madrina was Beatriz Villarreal.
Juana Javiera Narcisa Ecay Muzquiz, baptized 8 Nov 1739 in Monclova. Her padrino was Bartolome de Toralva, and her madrina was Juana de Ecay Muzquiz.
Maria Guadalupe Antonia Ecay Muzquiz, baptized 12 Dec 1740 in Santa Rosa de Lima. Her padrino was Joseph de _go, and her madrina was Juana Hernandez. She married Juan Nepomuceno de Alderete, son of Vicente de Alderete and Juana Rosa Ramon on 5 Feb 1770 in Santa Rosa.
Joseph Antonio Ecay Muzquiz, baptized 6 Jan 1742 in Santa Rosa de Lima. His padrino was Clemente de la Garza Falcon, and his madrina was Manuela Guerra Cañamar.
Blas Maria Ecay Muzquiz, baptized 3 May 1744 in Santa Rosa de Lima. His padrino was Clemente de la Garza Falcon, and his madrina was Manuela Guerra Cañamar. He married Juana Francisca Urrutia, daughter of Pedro Urrutia and Gertrudis Valdez.
Miguel Francisco Ecay Muzquiz, baptized 26 Oct 1746 in Santa Rosa de Lima. His padrino was Vicente de Alderete. He married Maria Gertrudis de Alderete, daughter of Vicente de Alderete and Maria Josefa Garcia de Rivera on 26 Feb 1781 in Santa Rosa.
Jose Maria Ecay Muzquiz, baptized 17 Mar 1748 in Santa Rosa de Lima. His padrino was Pablo Mauricio de la Garza, and his madrina was Philipa Rosa Martinez.
Francisco Javier Ecay Muzquiz, baptized 19 Feb 1750 in Santa Rosa de Lima.
Maria Gertrudis de la Luz Ecay Muzquiz, baptized 27 Sep 1752 in Santa Rosa de Lima. Her padrino was Joseph Conti, and her madrina was Marcela de la Garza.
Mariano Catalino Ecay Muzquiz, baptized 25 Nov 1758 in Santa Rosa de Lima. Her padrino was Javier de la Garza, and her madrina was Josepha Paredes.
was stationed at Presidio de Santa Rosa del Sacramento in February 1750, when he was appointed to investigate the site of the proposed San Francisco Xavier Presidio. He was instructed to take charge of the garrison at San Xavier, to measure the lands and water of the San Xavier (San Gabriel) River, to take a census of the mission Indians, and to do anything else pertinent to the determination of the necessity for a presidio. In June 1750 Ecay Múzquiz surveyed the San Xavier River, and his favorable report ended the doubt standing in the way of final consent to the establishment of the presidio. He turned the garrison over to the newly appointed presidial commander, Felipe Rábago y Terán, on December 13, 1751. On January 16, 1753, Ecay Múzquiz was appointed by the viceroy to assist Capt. Miguel de la Garza Falcón in the official inquiry into the murder of Fray Juan José Ganzábal of Nuestra Señora de la Candelaria Mission. After the death of his chief in August 1753 Ecay Múzquiz commanded the garrison until he was relieved by the new inspector, Pedro de Rábago y Terán, on August 11, 1754. In 1757 Ecay Múzquiz was assigned as lieutenant of the garrison of San Luis de las Amarillas Presidio (San Sabá). As official courier for the commandant, Diego Ortiz Parrilla, he carried dispatches, conducted a prisoner to Mexico City, and escorted a new parish priest from Presidio de Santa Rosa. By 1759 he had succeeded Toribio de Urrutia as commandant of San Antonio de Béxar Presidio at San Antonio and was a member of the junta that recommended Ortiz Parrilla's campaign to punish the allied northern Indians responsible for the San Sabá Mission attack in March 1758. When Ortiz Parrilla departed for Mexico at the conclusion of that campaign, Ecay Múzquiz was the logical choice to fill the San Sabá post in his absence. An illness prevented his doing so. Consequently, Capt. Manuel Rodríguez of San Juan Bautista Presidio took temporary command at San Sabá, where he remained until the arrival of Ortiz Parrilla's successor in 1761. (TSHA)