Marquis de Sade

Maybe it's because I've lead a sheltered life but I read about the
Marquis de Sade for the first time today.

I have been accused of being a sexual deviant myself in the past and maybe that's why my hackles arose when reading about him.

I'd like to find out more about him without watching any films about him like 120 days of salom that is an interpretation of his writing during ww2 many years after he died, I want something more realistic during the years he was alive, not a movie as such but any writings / research about the real
Marquis de Sade that will shock.