Gwendoline Christie Too Pretty for 'Game of Thrones'?

(L) Gwendoline Christie as Brienne of Tarth in "Game of Thrones" Season 3. (R) Gwendoline Christie attends the Elle Style Awards 2013 at The Savoy Hotel on February 11, 2013 in London, England. (Helen Sloan/HBO, Mike Marsland/WireImage)

Of the many indelible "Game of Thrones" characters, Brienne of Tarth must have been the trickiest to cast. She's described in the books as very tall, masculine, and very ugly.

The hit HBO drama's casting directors got lucky, though, when they found 6-foot-3 British actress Gwendoline Christie. The only problem? She was too pretty (more on that later).

As Brienne, Christie quickly became a fan favorite for her swagger and swordsmanship. This season, which premieres on March 31, Brienne will continue to knock around with Jaime Lannister (Nicolaj Coster-Waldau). "The journey those two human beings go on is extraordinary," Christie told Entertainment Weekly. "We see her in situations trying to survive in ways that extend beyond her physical strength. And we start to see her explore her womanhood."

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As intriguing as Brienne is, so too is her portrayer. Here are five things to know about the breakout "Game of Thrones" actress:

1. She was considered "too pretty" to play Brienne.

Some fans considered Christie too attractive for the role; in the books, Brienne is described as having crooked teeth, a flat chest, and an oft-broken nose. Christie, who was bullied about her height in her youth, was flattered.

"All my life, all I've ever wanted is for people to say -- first of all -- I'm pretty. But too pretty? It's amazing," she told EW.

"I also loved that they said, 'Who's this model?' I only ever wanted to be a model. This acting thing -- three years of drama school -- is an accident! I was like, 'Wow, they think I'm a model?' I didn't mind it at all."

[Related: What Does the 'Game of Thrones' Cast Really Look Like?]

2. She cried over her hair.

Brienne might be very masculine, but Christie was the opposite. "I'd always been someone that's had long blond hair, wore lots of makeup, dressed up, and wore high heels," she told SFX.

When she had to have it cut into the boyish style that Brienne wears, she cried for two hours. "It was very hard having that haircut," she admitted to the Huffington Post UK.

"It's very hard as a tall woman to remove your deliberately pronounced feminine aspects and look more masculine."

3. Before swinging a sword, she used to twirl a ribbon.

Before Christie got into acting, she was a semiprofessional rhythmic gymnast as a child. But as she explained to Access Hollywood, "I sustained an injury and strained all the muscles in my spine. When that happened, and I was told that I wouldn't be able to dance again at that level, I decided … I'd become an actress instead."

We know it's terrible form to applaud an injury, so let's just say we're glad that Christie turned lemons into lemonade.

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4. She lobbied for the part on Twitter.

Christie hadn't read the books, so she didn't know the role existed until her name started coming up in online chatter. So, she read them and immediately knew that she had to play Brienne.

"I wrote on Twitter that I wanted to play it," she told Access Hollywood. "I've never really done anything like that before, but I felt so passionate about the part."

See, tweeting really can be useful!

5. She worked out for six weeks … just to audition.

Christie knew that the role would be physically demanding, and she wanted to play Brienne so badly that she trained with a friend for six weeks before the audition.

"I started working out and lost a stone and a half," she revealed to SFX (for non-Brits, a stone and a half equals about 21 pounds).

"We did cardiovascular exercises, and I began to do yoga regularly. I stopped drinking, changed my diet entirely, and … I started kickboxing. I couldn't find any sword-fighting places."

Again, that was all before the audition. Once she landed the role, the training got really tough. Our muscles ache just thinking about it.

See Christie as Brienne on "Game of Thrones":

"Game of Thrones" Season 3 premieres Sunday, 3/31 at 9 PM on HBO.