His father was Bernabe de las Casas, and his mother was Maria Isabel de la Garza.
He married Ana Martinez Guajardo, daughter of Ignacio Martinez Guajardo and Maria Isabel Flores de Valdez.
Catarina de las Casas. She married Juan Garcia Saldivar, son of Gaspar Garcia.
Francisco de las Casas. He married Maria Josefa de Arrellano, daughter of Nicolas de Arellano and Rosa Maria de Arredondo. He married Jacinta Galvan.