Flamenca is a young and very beautiful woman. As such, she has a horde of suitors. She could have a king if she pleased. Or rather, if her father pleased. Which he does not. No, he decides he'd rather have her closer to home so he may visit her, so he marries her off to some guy he knows who instantly becomes infatuated with her.
Two issues, immediately: 1) her loving(?) father never does end up visiting her, and 2) her new husband is a little too obsessed with her. When a king shows too much affection for her (actually he assaults her), her husband becomes so jealous that he locks her and her ladies in a tower with only one window. There she stays for years, growing bitter and resentful of her tyrannical husband.
Still, her father does not visit her. No one tries to save her until a young and equally beautiful knight from another country hears of her plight and comes to her aid. He promptly acquires the role of a priest's clerk so that he may exchange a few words with Flamenca each church service--the only time she's allowed to leave her tower. Of course, compared to her awful husband and with no other real option, she falls in love with Guillem. And good thing, too, because I'm not sure he'd help her escape her tower for any amount of time otherwise. He'd probably just leave or...die of grief or something.
Anyway, though the hero isn't exactly selfless in his motives, I still enjoyed this story and am surprised it isn't more well-known to readers.