That’s a really long answer, we don’t know ALL that much about his backstory, just that he was a Marquis (never named) in a little rural village in France, so he has some local power/respect in title, but he’s really poor, is not a particularly good husband or father, he’s blind by the time Lestat is 21… and we know that he treated Lestat BADLY during his childhood. Louis described a little of his time living at Pointe du Lac in book!IWTV.

In short:

For more, read The Vampire Lestat (the Marquis is in the beginning)(gif below used for humor, not intended to be rude!) The Marquis is not mentioned again in any later book. He does not get to vampire.

There is some fanon that the Marquis’ physical abuse of Lestat extended further, but that’s not in canon. If that were true, it could be part of Lestat issues with relationships and consent.