Romo de Vivar

My 3x great grandfather was named Juan Romo de Vivar. He owned a hacienda just outside the city of Aguascalientes around 1884 called Hacienda Agostaderito. He married Rafaela Velasco in Calvillo, Aguascalientes in October 1842. They had two sons that I know of -- Jose Ana Romo Velasco and Miguel Romo Velasco (my 2x great grandfather) who was born in Aguascalientes in 1845. The family story is that Miguel lost the hacienda to gambling debts in the 1890s.

I have tried for years to find out who Juan Romo de Vivar's parents were, with no success. Can anyone help me discover who my 4x great grandparents were? Thanks.