I have no idea what you're referring to. The quote you posted I was guessing was the one used on the coins commemorating the killing of Christians at the St. Bartholomew massacre. If it was something else just be direct and say so.
Bartolome de las Casas is a proper name of a man who vbecane a Dominican friar and who argued for civil rights for native Americans whether or not they were Christian, much less Catholic. The behavior of the Spanish in the new world scandalized many Dominicans (and other Catholics) and prompted the development of what later would be considered international law. De las Casas didn't get ANY support (to speak of) from the Spanish laity in the New World and got the run around when he went back to Spain to plead for the Indios. And that's about all I know about it.