HBO plays a “Game of Thrones” with Lena Headey

The Game is on. HBO has greenlit the TV adaptation of the popular fantasy series Game of Thrones with Lena Headey.

HBO has ordered nine episodes plus the pilot of the new series based on the novels by George R.R. Martin. Called the “American Tolkien,” Martin’s acclaimed A Song of Ice and Fire series chronicles the epic power struggle in a mystical kingdom with kings, queens, knights, rogues, mercenaries and more. HBO has also released the first image from the production.

Lena has been cast as Cersei Lannister, “a woman of royal blood who is every bit as smart, cunning and devious as the powerful men around her.” Joining her in the cast will be Sean Bean as Eddard Stark, the patriarch of the noble Stark clan, and Jennifer Ehle as Catelyn Stark, his wife.

According to The Hollywood Reporter, the large cast (see a full list here) will begin production in Belfast this June. The pilot has already been shot. The series is then expected to debut on the premium channel in spring 2011. Each season is expected to span one of the four published books so far (another three are in the works).

Fans of the fantasy series have been anxiously watching the project’s developments. Known for its stark, often brutal realism, the series has the potential to be a Lord of the Rings-meets-The Sopranos of series TV. So, are you excited? Does it seem like a good fit for Lena? Heck, anything seems like a good fit with Lena — but maybe that’s just me.