As a drama school student, Kit Harrington landed the role of Albert in the National Theatre's adaptation of "War Horse," a role he reprised on the West End. Soon after, he scored his first TV role as the beloved Jon Snow.
Peter Dinklage has won two Emmys and a Golden Globe for his role as Tyrion Lannister on "GoT," but he made his film debut in 1995. His breakout role, however, came in 2003's "The Station Agent," and he appeared in "Elf" that same year.
Before playing Arya Stark, Maisie Williams had never acted professionally. Since then, the 19-year-old has added more credits to her name, including four episodes of "Doctor Who" and five feature films.
Sophie Turner also made her acting debut on "GoT," with the role of Sansa Stark. Since then, she's appeared in a number of films, including the upcoming "X-Men: Apocalypse."
Isaac Hempstead Wright made his film debut in "The Awakening" the same year he began playing Bran Stark. Though his character has been absent for a season, he is returning for the sixth season.
Nikolaj Coster-Waldau starred in numerous Danish films and TV shows before making his US debut as Gary Gordon in "Black Hawk Down." His portrayal of Jaime Lannister has introduced him to a wider audience.
Lena Headey made her film debut in "Waterland" in 1992. She went on to appear in films such as "300," and portrayed Sarah Connor in Fox's "The Sarah Connor Chronicles" before landing the role of Cersei Lannister.
Alfie Allen, known for playing Theon Greyjoy, made his debut in 1998 with the TV movies "You Are Here" and "Elizabeth," but didn't act again until 2004's "Agent Cody Banks 2."
Aiden Gillen starred in a number of roles before receiving critical acclaim for his role in the British series "Queer as Folk." Fans may also recognize the actor, who plays Petyr Baelish (Littlefinger), from HBO's "The Wire."
Natalie Dormer made her film debut in 2005's "Casanova." The actress, who plays Margaery Tyrell, is also well-known for portraying Anne Boleyn in "The Tudors."
Liam Cunningham made his film debut in 1992 and has appeared in films such as "A Little Princess," "Dog Soldiers," and "Clash of the Titans." He's been playing Davos Seaworth since 2012.
Gwendoline Christie began her career on stage in 2006, and made her film debut as a shopper in 2009's "The Imaginarium of Doctor Parnassus." Portraying Brienne of Tarth on "GoT" was her first major screen role.
Though well-known for the "Resident Evil" films, Iain Glen made his acting debut in an episode of Scottish detective drama "Taggart." His film debut was in 1988's "Paris by Night." He plays Ser Jorah Mormont on "GoT."
Carice van Houten has appeared in a number of Dutch films and TV series. Her first notable role was Suzy in the TV film "Suzy Q." She went on to star in "Black Book," "Valkyrie," and "Repo Man" before being cast as priestess Melisandre.
Michiel Huisman began his career in Dutch TV shows and films, even appearing alongside Carice van Houten in "Suzy Q" and "Black Book." His break in the US came with a starring role as Sonny in HBO's "Treme." He replaced Ed Skrein as Daario Naharis in season four of "GoT."
Indira Varma made her film debut in 1996's "Kama Sutra: A Tale of Love." Her other credits include "Bride and Prejudice" and TV series "Luther." She's played Ellaria Sand since season four.
Nathalie Emmanuel made her acting debut at the age of 10 in the West End production of "The Lion King," and then scored her first on-screen role in the British soap "Hollyoaks." She's been playing Missandei since 2013.
Iwan Rheon was 17 when he was cast in the Welsh-language soap "Pobol Y Cwm," but soon transitioned to the stage. He was cast as Moritz Stiefel in the London production of "Spring Awakening," and won an Olivier Award for his performance. Directly after that, he was cast in "Misfits," and now he stars as the sadistic and much-hated Ramsay Bolton.
Hannah Murray began her professional career in the British teen drama "Skins." She's played Gilly since season two of "Game of Thrones."
Before playing Samwell Tarly on "GoT," John Bradley portrayed a cardinal on the historical TV drama "Borgia."
