He was born circa 1567. His father was Baltazar Castaño de Sosa, and his mother was Inez Rodriguez.
He married Sebastiana de Treviño, daughter of Juan de Farias and Maria Ana de Treviño Quintanilla.
Maria Rodriguez. She married Gonzalo Fernandez de Castro, son of Juan Fernandez de Castro and Mayor de Renteria.
Monica Rodriguez Treviño. She married Miguel de Montemayor, son of Alberto del Canto and Estefana de Montemayor y Porcallo.
Andrea Rodriguez. She married Fernan Blas Perez.
One of the 12 original settlers of Monterrey. First alcalde mayor of Monterrey. Registered 4 mines "en la serrania", 24 Jan 1598. Registered 3 mines in Ntra. Sra. de la Asuncion, in the cerro of San Lucas, Candelaria vein, 2 Feb 1599. Gave Diego de Montemayor 4 caballerias of land between the Silla and Santa Catalina rivers, in exchange for 4 others by the Pesqueria Chica, in las Tapiezuelas, 30 Sep. 1601. Gave 4 caballerias of land to Capt. Bernabe de las Casas (husband of his niece) in the villa of San Juan Bautista, 1609.