Throughout Hollywood there have been famous actress-director relationships, some of which ended up powerhouse couples... and then later on divorces. However, the relationship between Keira Knightley and Joe Wright is at its strongest, and making us miss their collaborations as the years go on. But can we just say how pleased we are they didn't marry one another?

Take for example Woody Allen and Mia Farrow. They worked on movies like Rosemary's Baby, and were in a relationship for 12 years in which Farrow starred in 13 of Allen's movies. Sam Mendes and Kate Winslet were married when she starred in his film Revolutionary Road, but they split two years after. Most famous of all is Helena Bonham Carter's work with her husband Tim Burton, but they divorced after 13 years and making six films together.

So thank the period drama gods that Keira Knightley and Joe Wright didn't follow in the same pattern. If they did, who knows, but we might not have gotten any more of their collaborations if they've had to split. Instead, their friendship is still strong and most of us are still waiting to get another movie from them.

All three of Wright's movies with Knightley have inspired tons of girls night ins all over the world, and are on the list of most watched period dramas. The first time Wright and Knightley worked together was on Wright's adaptation of Jane Austen's classic Pride and Prejudice in 2005, where Knightley gave a passionate performance as leading lady Elizabeth Bennet, earning her an Oscar nomination.

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Two years later Wright called Knightley back to star in his World War II period drama, Atonement, based off of Ian McEwan's book. This film was more tragic and did not have a happy ending so much like Pride and Prejudice. Instead, Knightley's leading lady character Cecilia and her beau Robbie meet tragic ends.

More recently they have worked together on Wright's Anna Karenina in 2012, which was also based off of a book, this time by Leo Tolstoy. Anna met a similar fate as Cecilia, but was heart broken as well, after her beau Vronsky seems to fall out of love with her. "We have worked three times, and he has killed me twice," Knightley told USA Today.

Anna Karenina also proved to be more of a high-scale production compared with the other two. Anna Karenina was way more theatrical, with the entire movie seemingly acted out on one large moving set. Atonement and Pride and Prejudice on the other hand had more natural settings in the country side and at stately homes.

The fact that all of their collaborations are period dramas, though, seems to disgruntle Wright however. He doesn't agree with the label the pair's work has been given. "I like to think of them as being fantasies," Wright told USA Today. "I'm not interested in historical re-enactment. They allow us to dream and think in more expressive ways."

Wright and Knightley's relationship though couldn't be more platonic, in fact, it's even more of a brother-sister relationship. Around the time that Anna Karenina came out in 2012 the pair even lived a couple doors down from one another. Wright calls Knightley "my sister in celluloid," which is probably why they work so well together.

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"It feels like we've grown up together," Wright continued. "We've seen each other through some good times and some bad times, and that's a lovely process. I like the idea of working with someone who has seen me at my weakest and also with success."

Like all siblings though, the pair often get into arguments just as much as they've worked well together. They once had an argument about which role Knightley would take in Atonement, when Wright wanted her as leading lady Cecilia, and subjected her to many hours of learning the choreography for the dancing in Anna Karenina.  But no matter what they always made up in the end.

"He understands what I'm talking about," Knightley continued. "We do argue occasionally, and like siblings, you kind of know that you have to get over the argument because you're not going to stop being siblings. And so it's never the end of the world when you argue. There is a trust in the fact that underneath anything that is going on, you're still going to love each other."

The fact that the pair consider each other siblings is a comfort, because they were both prone to dating people working on the same movies. The pair actually went on to have relationships with their Pride and Prejudice cast mates. Knightley started a relationship with Rupert Friend, and Wright dated Rosamund Pike. But now in recent years the pair have both instead married musicians.

Now looking back years later, it's astounding to hear that Wright and Knightley's first meeting didn't go well at all. Knightley told BAFTA Guru that she didn't even want to be cast in Pride and Prejudice because it was her favorite book, and she wouldn't have been able to take the rejection if she hadn't got it. Wright's rude attitude toward her was obvious as well. Both of them went into the project not wanting to do it with the other.

Fortunately, they managed to meet about it again and after that, Knightley said something just clicked, and they established their relationship's dynamic. Sadly there's been no developments on the pair working together again in the near future, but that's not stopping us from keeping those three movies in heavy rotation.

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