I thought I already posted in this topic...
Manga to Anime? Mitsuki Oosawa's "Seisen no Keifu"... yeah...
"Once upon a time there was a beautiful princess..."
Quick rundown of that manga: Violent. Flowery. (Like a Shoujo almost, but WAAAY TOO violent). Romantic and overly sexual (but not fanservicey)... and tragic... very very tragic.
It starts with our main character (a badass white-knight guy) riding off to save his childhood friend, and would soon meet a woman with an ill omen that'd soon become his wife... it all gets darker from there... then horrible, horrible things (mostly involving fire) happen, and then there's a time-skip... and things are even worse, the original cast (save 1 guy and the aforementioned childhood friend of the hero) are all dead, there's an evil god that eats children... and we're left with the hero's son, who goes off to set things right, which consists of more of the same with less "die in fire". As bit of a note 3 of the pairings (it is something of a romance) are incest, although a taboo against incest is present, the main character (both of them) is (are) firmly against such foolish ways... 2 of said pairings are horrifically tragic (one ends with a certain "Lord Brother" getting beheadded (and his head getting catapulted into the good guy's castle), the other, the woman ends up getting torn to bloody shreds by that evil god (which was summoned by her son))...
Oh and here's a "cover image" from it.
(Catch who's behind this thing?)