He was born circa 1730, and was baptized 23 Feb 1730 in Saltillo. His father was Pedro de Alderete, and his mother was Josefa de Yrigoyen. His padrino was Antonio Cortinas, and his madrina was Maria de Urandain. Birth source: link
He married Maria Catarina de Cardenas, daughter of Gaspar de Cardenas and Bernarda Ramos de Arriola on 13 May 1754 in Saltillo. He was 24 years old. Marriage source: link.