The Black Legend of La Croesia

La Croesia was known as a very pious woman by the time of her death. She's married off first to one dude who is politically convenient. He's also related to somebody who helped Alexander VI become the Pope. But after a couple of years, it's decided that actually there's a more advantageous marriage for her. So the marriage has to be annulled. And so she's then married to another guy, another sort of important family connection. He is murdered by her brother Cesare,. or he's the most likely candidate for having murdered him.