His descendants have spread across the world including Western Australia. I(the compiler ) am a ggg-grandson. As far as I know the only two living descendants born with the Castilla family name live in Western Australia. I am not aware of any male descendants with the Castilla family name anywhere in the world!
My journey to trace my ancestors began in 2009 when I started to go through my father's notes and papers on the de Castilla family. There was very little information on Mariano, Rebecca and their children except for my gg-grandfather Henry M Castilla downwards, and some of this "family knowledge" was partly or totally incorrect.
From these sketchy beginnings we have been able to build an extensive descendancy and in specific areas pictures of their lives.