"Hunger Games" finds Cressida in "Game of Thrones" star Natalie Dormer Natalie Dormer plays Margaery Tyrell, betrothed to marry King Joffrey Baratheon, on "Game of Thrones." HBO; Jason Merritt / Getty Images "The Hunger Games" has found its Cressida in "Game of Thrones" actress Natalie Dormer. The 31-year-old English actress has been cast in the two-part feature adaptation of the final installment in Suzanne Collins bestselling trilogy of books, "Mockingjay." She'll play a filmmaker who follows the heroic Katniss Everdeen (Jennifer Lawrence), attempting to document her efforts to overthrow the sinister Capitol government. Dormer had a small role in "Captain America: The First Avenger," but she's arguably best known to genre audiences for her performance on HBO's lavish fantasy "Game of Thrones," in which she plays Margaery Tyrell, the savvy bride-to-be of the ruthless King Joffrey (Jack Gleeson). D.B. Weiss, who created "Game of Thrones" with fellow show runner David Benioff, said Dormer was such a strong actress they opted to expand Margaery's role in the narrative from what initially appeared in the George R.R. Martin novels that inspired the series. "Margaery has a very ancillary role in the books," Weiss told Hero Complex earlier this year. Then we cast Natalie, and we realized immediately that we couldn't keep it that way. You can't have that big an acting asset and leave it in the background, so you clear out space in the story to make room for her as a fully fledged character. Dormer was also featured in Showtime's period drama "The Tudors." The next cinematic chapter in the "Hunger Games" saga, "The Hunger Games: Catching Fire," reaches theaters Nov. 22, and star Lawrence, speaking last month at San Diego's Comic-Con International, said the movie finds Katniss grappling with how to return to her normal life in the wake of her victory in the first film. She's adapting to a new life," Lawrence said. Director Francis Lawrence (no relation) is set to direct "Catching Fire," and both "Mockingjay" installments.