Denise Gough as Missy, left, and Keira Knightley in the title role of "Colette." 

She was the J.K. Rowling of her day. Only, for a long time, nobody knew it.

The author known as Colette wrote a string of huge bestsellers in France around the turn of the 20th century and beyond. Her four early novels, about a young woman named Claudine, were massive hits. Readers not only devoured the books but bought Claudine-branded lingerie, hand cream and candies, and women began styling their hair after the literary heroine’s ‘do.

But Colette’s name wasn’t on the books. Instead, she ghost-wrote them for her husband, who told her that “female authors don’t sell.” While he took all the glory (and, eventually, all of the money), she toiled away on the books in obscurity.

“Colette” is the story of a very unconventional marriage and literary partnership, with Keira Knightley making a very engaging Colette. Colette’s real life gives writer-director Wash Westmoreland (“Still Alice”) a lot of material to work with – in addition to an author, she was also a performer at the notorious Moulin Rouge. This is one of the movies where you check Wikipedia afterwards to see “Did that really happen?” More often than not, it did.

We first meet Sidonie Gabrielle-Colette as a small-town French girl, wooed by the worldly and randy author Henry Gauthier-Villars, aka “Willy” (Dominick West of “The Wire”). He married her and takes her to Paris, and introduces her to a world of debauched parties and libertine pleasures. She proves to be more than game to go along with Willy’s proclivities, and their relationship has a headmaster-eager pupil edge to it.

Colette also learns that Willy doesn’t really write his own books, but employs a stable of writers to turn his ideas and outlines into novels. Eventually, she decides to give it a try, and with his guidance as to what will sell in the marketplace, creates the first Claudine novel.

As she writes more and more novels, the line between marriage and literary partnership becomes blurred. It would be easy to paint Willy as an overt villain, but West’s sly performance is more complex than that. He is certainly exploiting Colette’s talents for his own gain, but he also loves her in his own way. He just doesn’t know what it’s like to love someone as an equal. And it turns out Colette is more than a match for him.

As the years go by, the headmaster-pupil relationship grows tiresome for Colette, who yearns for freedom (and discovers herself becoming more attracted to women). Her literary and emotional emancipation from Willy becomes the heart of “Colette,” and Knightley brings fire and conviction to her performance as Colette. As Colette said in an interview years later, “What a wonderful life I had. If only I had realized it sooner.”

Rob Thomas is the features editor and social media editor for the Capital Times, as well as its film critic. He joined the Cap Times in 1999 and has written about movies, music, food and books.