The best sources I've found for Eleanor of Aquitaine are Dan Jones' book on the Plantagenets and Alison Weir's biography Eleanor of Aquitaine.

To give the sweeping generalization, Eleanor of Aquitaine was the Duchess of Aquitaine and was a political powerhouse in her own right. While her court was not as into the Courts of Love as I suspect many people like to think, it was a more relaxed court compared to many, and she was a well-known sponsor of the arts. She was convinced to marry Louis VII, but the marriage was a shambles. He was infatuated with her, but as a younger son, he'd been raised to go into the church. He was deeply religious and would rather pray than enjoy music, and he supposedly felt guilty having sex with her. Whatever fondness Eleanor had for him at the beginning of the relationship quickly faded. The two went on Crusade together, and their relationship got even worse. There are rumors to this day (Weir seems to believe them, though Jones and other historians do not) that Eleanor had an affair with her uncle while on Crusade.

We don't have details as to how it happened, but by the time she and Louis divorced, she was ready to marry Henry II of England. Whereas with Louis, she had multiple daughters and no sons, with Henry she soon had five sons. This, of course, upset Louis, who first had to lose his beloved wife to an upstart and then had to find out she had sons for that king while she didn't do so for him.

Henry II, though, was huge on power but small on sharing it. Not only did he give away some of Eleanor's lands - which he didn't actually have, because they went from her to her offspring - but he wouldn't give the expected power, land, or income to his children, who soon grew resentful. Eleanor helped them try to overthrow Henry with Louis's help, and when she tried to escape England was captured dressed as a man. Henry couldn't kill her, but he did imprison her. During this time, she and her maid were given the same clothes to wear and likely had to share a bed (though it wasn't uncommon for people to share beds, they were typically of the same social class). Henry also tried to divorce her on the grounds that Eleanor slept with his father before she married Henry (in part because of her power and in part because of her looks, Eleanor was a prime target for talks about her sexual escapades).

After Henry's death, her captors released her before Richard the Lionheart could demand they do so, afraid of what Richard might do to them otherwise. Eleanor was restored to glory as Queen Mother, and her reputation experienced as huge shift. People who formerly hated her and thought she was a whore now talked about her virtue and wisdom. This was aided by how Eleanor ran the country on Richard's behalf, helping to make him one of the most popular kings in British history. After Richard's death, she tried to advise John as well to mixed results. After Eleanor's death, her reputation fell again to the point that Shakespeare and the Pre-Raphaelites dumped on her.

That's off the top of my head, but you'll find so much more in the books.