Gwendoline Christie Gwendoline Christie

British actress Gwendoline Christie has joined the growing cast of Game of Thrones, book author George R.R. Martin announced on his blog.

Christie, who appeared in The Imaginarium of Doctor Parnassus, will play Brienne, Maid of Tarth to the late king's brother, Renly (Gethin Anthony). Though she's not physically attractive — she's described as a large and piggish-looking woman — she is a great fighter and is very loyal to Renly.

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"This was another one of those cases where there was hardly any debate," Martin said on the casting. "The day the first batch of auditions went up for the role, we looked at a dozen actresses who were reading for Brienne and one actress who WAS Brienne."

Christie joins Tudors alum Natalie Dormer, who just signed on to play Margaery Tyrell, who is pledged to marry Renly.