He was born circa 1744, and was baptized 3 May 1744 in Santa Rosa de Lima. His father was Jose Joaquin de Ecay Muzquiz, and his mother was Mariana de la Garza Falcon. His padrino was Clemente de la Garza Falcon, and his madrina was Manuela Guerra Cañamar. Birth source: link
He married Juana Francisca Urrutia, daughter of Pedro Urrutia and Gertrudis Valdez. It was her second marriage.