Rayder, “the King Beyond the Wall,” was once a member of the Night’s Watch before abandoning his post to lead the Wildlings. Though he was referenced several times throughout the series’ second season, and Jon Snow (Kit Harington) was taken to meet him during the finale, he had yet to appear on the show.
Hinds is no stranger to HBO. He played Julius Caesar on Rome, from 2005 to 2007. Most recently he’s played Bill Clinton-esque figure Bud Hammond on USA miniseries Political Animals.
Read about more third season additions to Game of Thrones here.