Natalie Dormer is the clever, glamorous Queen Margaery Tyrell.
She's no stranger to royalty. Dormer got her start as the clever, glamorous wife of King Henry VIII, Anne Boleyn, on Showtime's "The Tudors."
Dame Diana Rigg is excellent as the calculating and caustic matriarch Olenna Tyrell.
Rigg enchanted audiences decades earlier as Emma Peel in the '60s spy series "The Avengers."
As Lord Tywin Lannister, Charles Dance ruled King's Landing without ever having to sit on the Iron Throne.
Dance played a much softer English gentleman in the miniseries "Rebecca," alongside the future Queen of Thorns herself, Diana Rigg.
Lena Headey is an excellent villainess as the scheming, vengeful Queen Cersei.
She showed audiences that she could play a much more sympathetic ruler as Gorgo, queen of Sparta, in "300."
Mark Addy was the ruling King of the Seven Kingdoms, Robert Baratheon, when the show began.
The actor was once cast as the cheerful squire, Roland, in 2001's "A Knight's Tale."
For the first four seasons, Jack Gleeson played King Joffrey, one of the most hated characters in Westeros.
But the actor got his start as an adorable, innocent young boy in the first film of the "Dark Knight" trilogy: "Batman Begins."
Lancel Lannister (Eugene Simon) has become a serious threat to the crown since joining the High Sparrow.
Simon got his start alongside Vanessa Hudgens in the Nickelodeon show "House of Anubis."
"Littlefinger" (Aidan Gillen) is a master schemer and political strategist.
But, in another life, he was a lawyer on the acclaimed crime drama "The Wire."
Natalia Tena debuted in season one as Osha, a wild woman eventually charged with protecting the youngest Stark child.
Years earlier, she was the similarly strong-willed Nymphadora Tonks in the "Harry Potter" film series.
Maester Pycelle is mostly known for his cautious, largely useless advice as a member of the small council in King's Landing.
Actor Julian Glover had a small supporting role as a military adviser in "The Empire Strikes Back."
At 6 feet 6 inches, Rory McCann is terrifying and imposing as "The Hound."
He appeared years earlier in action-comedy "Hot Fuzz" as a terrifying, imposing — and hilarious — grocery-store cashier.
Arya (Maisie Williams) has traveled a long, brutal road, but her journey still isn't over.
The show was Williams' first big role. Here's a throwback to herself as a child she posted to Instagram.
Jason Momoa led the khalasar of fearsome warriors as Khal Drogo.
But the Samoan actor starred as a — much less cool — "Baywatch" hunk in his younger years.
Today, Emilia Clarke is known to most as the Mother of Dragons, Daenerys Targaryen.
In real life, Clarke's a brunette. One of her early roles was in a made-for-TV movie called "Triassic Adventure."
Iain Glen is the disgraced Ser Jorah Mormont, now motivated almost entirely by his love for Daenerys.
Glen once faced down Angelina Jolie in "Lara Croft: Tomb Raider."
Nathalie Emmanuel plays Missandei, a beautiful multilinguist and one of the few people in Meereen whom Daenerys actually trusts.
The English actress got her start playing Sasha Valentine in the English drama "Hollyoaks."
Sophie Turner's first big role was playing Lady Sansa Stark of Winterfell, but had a long way to go before becoming as strong as she is now.
Here's a throwback she shared of herself on Instagram when she was younger.
Gwendoline Christie is a ferociously loyal knight instrumental in returning the Stark family to the North.
She got her start as the much more refined "Classy Shopper #2" in "The Imaginarium of Doctor Parnassus."
Stephen Dillane led his armies to war as Stannis "The Mannis" Baratheon on the show.
He had a well-regarded earlier role opposite Nicole Kidman in "The Hours," as Leonard Woolf, husband to classic poet Virginia Woolf.
Liam Cunningham is the loyal second in command to Stannis Baratheon.
Decades ago, he played a loyal knight to Sean Connery's King Arthur in "First Knight."