In a startling career pivot, former professional rugby player Peter Claffey has been catapulted from the sporting arena to the heart of one of television's most formidable franchises. The Irish actor is set to lead HBO's highly anticipated new Game of Thrones spinoff, 'A Knight of the Seven Kingdoms', premiering on Sky Atlantic and NOW from 19 January 2026. Yet his journey to becoming Ser Duncan the Tall was marked not by celebration, but by a profound and physical anxiety attack.
A Physical Reaction to a Life-Changing Role
Claffey's big break arrived without the typical fanfare. Upon learning he had secured the lead role, the actor was in a Belfast costume fitting. The news triggered an intense physical reaction. "I was pissing sweat," Claffey admits. "[I thought] my heart can’t actually beat any faster." He subsequently rushed to a bathroom and vomited violently, comparing the episode to a famously exaggerated scene from Team America: World Police. "It was a f***ing rollercoaster," he recalls.
The stress had been building throughout the audition process, severely impacting his health. After the confirmatory call from his agents, his girlfriend found him on the floor at home, "sheet white, curled into the fetal position." Claffey confesses, "I just had a bit of a meltdown. What should have been such a beautiful, amazing experience just turned into one of the worst days I’ve ever had in my life." The incident prompted a "spiritual journey" to confront his severe anxiety, from which he now says he is in "great health."
From Rugby Jock to Self-Professed Nerd
Claffey's casting as the gentle giant Ser Duncan seems apt. At 6ft 5in and built like an "industrial fridge," his physique is a legacy of his previous life as a professional rugby player. By 19, he was a 119kg force on the field, earning a spot on the Ireland U20s team and later a development contract with Connacht Rugby. However, he found the experience isolating and his identity became solely tied to sport.
"It was probably the most isolating, lonely year I’ve ever had," he says of his time with Connacht. "My whole identity became just being a rugby player." This contrasts sharply with the man seen today, who describes himself as a "complete f***ing nerd" and who found creative solace in sketch comedy on Instagram. "I definitely feel a lot happier now than I did when I was playing rugby, for sure," he states.
Stepping into the Dragon's Den: Pressure and Passion
Claffey is acutely aware of the immense pressure attached to the Game of Thrones universe, especially following the divisive reaction to the original series' finale in 2019. "I was obsessed with the original series," he admits. "I was one of those people that was like, that ending wasn’t good enough." This history makes leading the new prequel, based on George R.R. Martin's "Dunk and Egg" novellas, a daunting prospect.
"It’s totally terrifying," Claffey explains, "because it’s not like it’s an original product and it's also not something that I don't give a s*** about. I really, really want to get things right for this." Set roughly 90 years before the events of Game of Thrones, the series follows the soft-hearted hedge knight Ser Duncan the Tall and his wise, bald squire "Egg," played by Dexter Sol Ansell.
Despite his anxieties, Claffey embraced the franchise's signature grit. He was hoping his character would receive a "classic Thrones beatdown" and that the show would be "as gruesome as possible." His primary goal is to do justice to the source material and its creator, George R.R. Martin, with whom he has a "decent relationship." For the man who once questioned his identity beyond rugby, the answer has arrived—sweat, fear, vomiting, and all.
