Blas Cantu was born in Valle de Salinas, the son of Fernando Cantu and Maria de Villarreal.
He requested a dispensation to marry Ana Maria de la Garza in 1730. Dispensation source: Guerra et al., Index to the Marriage Investigations of the Diocese of Guadalajara, p.91.
He requested a dispensation to marry Maria Ignacia de Treviño in 1751. Dispensation source: Guerra et al., Index to the Marriage Investigations of the Diocese of Guadalajara, p.141.