One look at A Knight of the Seven Kingdoms star Peter Claffey and you can imagine him playing a knight: You see the shoulders that could carry the weight of plate armor, the frame built for swinging a sword.
In HBO’s new Game of Thrones prequel, the 29-year-old plays Ser Duncan the Tall, a young man with pure ideas about heroism that the world of Westeros can’t wait to challenge. The series is based on the three charming and profound Tales of Dunk and Egg novellas by George R.R. Martin, which are less sprawling stories than those in the main A Song of Ice and Fire novels that inspired Game of Thrones.
Unlikely friends Egg (played by Dexter Sol Ansell on the series) and Ser Duncan, aka Dunk, deal with serious imposter syndrome as they encounter some of the most powerful people in Westeros, who tend to range from dismissive to exploitative to cruel. Dunk is constantly reminded of how hard it is to rise above one’s perceived station, no matter how tall you are.
Claffey understands disappointment. In 2019, he was cut from the rugby team in Connacht, the Irish province where he was born. At 6’5, he was the team’s lock, a position reserved for the tallest and strongest players.
Rugby had shaped who he was since boyhood, and being cut felt like losing touch with part of himself.
“I left rugby in a strange way. I hadn’t fulfilled what I thought I would, and it was such a big part of my identity that leaving it was hard,” he says. “That final year was awful — I felt isolated. It wasn’t anyone’s fault. It’s just how those team environments can be. I felt alone and bitter afterward and didn’t want to hear about rugby for a long time.”
He went home, but home didn’t know what to do with him: He felt like people only saw a player who no longer played.
“When I went back to my hometown, everyone knew me as a rugby player since I was 11,” he explains. “People didn’t understand what I was doing. I’m from small-town, traditional Ireland. Being in the arts, acting, isn’t seen the same way. … It was tough breaking through that.”
So he started over. In 2020, he went to acting school at the Bow Street Academy in Dublin. He started from zero, and even played a little rugby again — but “had fallen out of love with the sport.”
“For a long time, I considered it a waste, thinking I hadn’t gone to college or earned a degree and that I’d put everything into rugby with nothing to show for it,” he says.
Peter Claffey on His Journey to A Knight of the Seven Kingdoms
He made his stage debut in Tom Murphy’s A Whistle in the Dark at Dublin’s Abbey Theatre in 2022, and landed roles in Apple TV’s Bad Sisters, BBC Three’s Wreck, and Netflix’s Vikings: Valhalla.
Along the way, something surprising happened: His old calling helped him in his new one.
“Over time, I realized the discipline and work ethic from rugby really served me,” he explains.
The long, grueling days on set? He was built for them. The pressure? He knew it well.
“The ability to appreciate others’ roles and work as a team — that helped me become the kind of actor I want to be. The kind who doesn’t make things about himself. That teamwork mentality came directly from rugby.”
A commitment to teamwork helped him adjust to his leading role in A Knight of the Seven Kingdoms.
“It was massive,” Claffey says of landing the part. “I was really worried and nervous. I’d only ever done side characters before. A four-day week of intense shooting would leave me completely wiped out. So I wondered, ‘How am I going to do this for four or five months?’ It was terrifying.”
He learned to find the quiet center in the chaos of Martin’s world — even when that chaos was a deafening industrial fan meant to simulate a medieval gale.
“It didn’t feel very medieval,” he laughs, “but it looks very medieval on screen.”
Claffey is aware that he casts a long shadow. But he’s determined to be known for more than just his size.
“I’m always trying to break the mold a bit,” he says. “I want to show range.”
Claffey says his process of dealing with the disappointment of leaving rugby has been “a work in progress,” but adds, “I’m in a much better, more controlled place now.”
Peter Claffey on Learning From Cillian Murphy
A pivotal moment in that journey came on the set of 2024’s Small Things Like These, where he found a guiding light in his fellow Irishman, Cillian Murphy.
“Meeting Cillian was poignant,” Claffey says. “He’s someone I’ve admired my entire life as a film lover, and he turned out to be so down to earth.”
He particularly took note of the Oppenheimer Best Actor winner’s focus, attention to detail, and care for the craft. But what resonated most was Murphy’s philosophy off-screen.
“I’ve always admired how private he is,” Claffey says. “We live in this era of oversharing, which can dilute the mystery. I love that Cillian avoids that.”
He wouldn’t mind following Murphy – who once auditioned for the role of Batman and ended up playing the Scarecrow in Christopher Nolan’s 2005 Batman Begins — to Gotham City.
“I’m obsessed with superheroes,” he says. “If a role came along in that world, it would be amazing. … I especially love Batman. I think everyone secretly wants to play him.”
A Knight of the Seven Kingdoms premieres on HBO Sunday.
Main image: Peter Claffey behind the scenes of A Knight of the Seven Kingdoms. Photo by Steffan Hill/HBO