Alistair Petrie is no stranger to villains. The British star has played some of television’s most notorious, especially as the stone-faced, unfeeling headteacher Mr. Groff in smash hit series Sex Education, which saw his icy glare pierce through screens in over 55 million households worldwide across its four seasons.

But as hardcore fans of Netflix’s sex-positive teen dramedy might remember, Michael Groff’s redemption arc was undeniably one of the show’s more moving plot points. Petrie’s character, once practically vibrating with resentment and shame, learns to shed his steely exterior and make amends with his son Adam (Connor Swindells), with whom he had a fraught relationship. It’s an ending only made possible by the work of Petrie who, unlike the men he often portrays, is attentive, warm and softened by a palpable adoration of the craft.

“I think the villainous roles are hugely fun to play, but a lot of a lot of them can be underwritten from time to time,” confesses Petrie, also known for roles in Star Wars spinoff Andor and the BBC’s Sherlock. “The hero’s journey needs to be figured out and the villains can sometimes [fall] by the wayside. That’s what I find so entertaining when I read them — certainly the ones I take on — because you think: ‘Who is the human being? Where’s the villainy come from?’ It doesn’t just appear,” he continues to The Hollywood Reporter over Zoom in late September. “And in that sense, you’re being asked to elevate the material from where it was originally conceived. Every good story needs a villain, and how do you fulfill that? You try and find the human being within it.”

It’s this search for humanity that makes Petrie the perfect fit for theater’s biggest baddie: King Claudius, uncle to Shakespeare’s Prince Hamlet. The 55-year-old leads a mighty ensemble cast currently performing at the National’s Lyttelton Theatre until November, with Life of Pi‘s Hiran Abeysekera embodying our protagonist with a mischievous sense of frenzy through Robert Hastie’s sharp, contemporary take on the classic.

“What I love about playing Claudius on stage is that he has such main character energy,” says Petrie about the king-slayer, whose act of fratricide in a bid for the Danish throne sends his nephew spiraling. “When the curtain goes up, Claudius firmly believes that he’s in a play called Claudius. He’s not in a play called Hamlet. This is his moment.”

It’s something that Petrie finds brilliantly inspiring on the stage, a place he describes as “an amazing actor’s medium, whereas film and television are much more of a director’s medium.” Hamlet marks his return to theater after 11 years, and the Brit casts his mind back to a stint in Declan Donnellan’s West End production of Shakespeare in Love, in which he played Lord Wessex.

It’s not an experience he thinks back on entirely fondly, as Petrie found himself pulled between the painstaking demands of theater and family life. “I’m certainly not frightened of hard work — I revel in it — but I value my other real-life roles as a partner and a husband and a father,” he explains. “I blithely thought that you can live slightly out of London and still commute in and quickly do a West End Show in front of an audience and then just pop home and carry on as normal. But you can’t. It requires extraordinary reserves of energy, really, and something had to give.”

Petrie, married to actress Lucy Scott with whom he shares three sons, also admittedly found himself a little bogged down by the expectations placed upon the cast in the stage adaptation of the Oscar-winning film Shakespeare in Love (1998). “It was a very big-budget show. It had very grand plans. It was sort of Disney-backed,” he says, “and I think the expectations were so high and that was slightly thrust onto us. … When we finally finished, I had no desire to step on stage again. It wasn’t so much the doing of it. It was more [about] how it collides with your life, and I just wasn’t prepared to give that up.”

With his theatrical mojo rediscovered, Petrie finds himself back in front of a live audience. And after over a decade away, he’s relishing the thrill. “As an actor, I love the sense of being part of of a group, of an ensemble,” he says. “I do think if we search for anything in life, we do look to belong somewhere — I mean, a psychologist could have field day with me,” he jokes, “but I think it’s very much tied into the notion of being brought up as a military kid and moving around a lot. You’re desperate to fit in, and as soon as you find yourself as a part of something, you’re on to the next thing. There’s a certain masochism to being an actor.”

One set that Petrie found himself immediately at home on was the fan-favorite Sex Education, an experience that he continues to feel the ramifications of to this day. “It permeates throughout everything in the most glorious way. Sex Education is a gift — not was a gift. I put it in the present tense,” the actor says about his time as Mr. Groff.

In the early throes of production when fellow cast members Asa Butterfield, Emma Mackey, Ncuti Gatwa, Aimee Lou Wood and Connor Swindells were yet to reach the dizzy heights of stardom, he admits there were concerns about how the show would land with Netflix audiences. “Given the explosion of all the streamers and all the platforms and all the curation that people could do,” says Petrie, “would we find an audience? Or would we be buried in some kind of algorithm, in the bowels of Netflix? And it was just the most glorious reverse,” he smiles about the show, which debuted to critical and audience acclaim. “You couldn’t have predicted how people would receive it, of all age groups and demographics all over the world.”

Sex Education is a part of his life Petrie would never abandon in the face of snobbery, notably because it’s provided him with some of the strongest off-screen relationships of his career. In particular, Petrie is close with his on-screen son and Barbie actor Swindells, and last year officiated his wedding to fellow thespian Amber Anderson.

“I talk to Connor literally every day,” says Petrie. He pauses, recalling his first few days on the Sex Ed set. “I am absolutely a 50-something-year-old man trapped in a 22-year-old person’s body. There’s no question I’m a complete labrador when it comes to working in this industry. And within seconds, I thought, ‘Oh, this is going to be great.’ We were just one happy gang. I couldn’t give a rat’s ass whether I was comfortably nearly double their age — watching them all soar as they are, I look on it with almost a parental pride.” He’s working on a new series with Sex Ed alumn George Robinson, Petrie tells THR, who fans will know as Isaac Goodwin.

But Mr. Groff was a role that nearly escaped him. In 2019, Petrie found himself down to the final two for Prince Philip in another Netflix behemoth: The Crown. The part eventually went to Tobias Menzies, but disappointment was soon eclipsed by a phone call asking him to read for a thrilling new show about the sex lives of eager teens.

“The scripts were obviously so good,” Petrie says about the material crafted by The Crown mastermind Peter Morgan. “I thought, ‘Gosh, this is a character I really want to to investigate. Tobias and I are different, and it was either going to be him or it was going to be me. And he was magnificent — he’s a mate and a wonderful actor — and when I saw it, it made perfect sense to me.” Within an hour of being told Menzies nabbed the role, Petrie got the call about Groff. “Serendipity hovers over my being quite a lot,” he says, “and I will accept that. If serendipity is my God, I’ll take it.”

Another serendipitous development that’s got Petrie excited is the upcoming second season of The Night Manager with Tom Hiddleston, the British spy thriller adapted from John le Carré’s 1993 novel. In the first season, which had us gripped all the way back in 2016, Petrie played Lord Alexander “Sandy” Langbourne, financial director to the cunning Richard Roper (Hugh Laurie).

What was supposed to be a miniseries is now returning on Amazon Prime Video for a hotly anticipated second installment that, at certain points, didn’t involve Petrie at all. “I would get a phone call probably about once a year: ‘We think we’re on,’” says the Briton. “I was like, ‘Great.’ And then I get a phone call about a year later, and it would be like, ‘We are going to do it, but you’re not in it.’ I went, ‘That’s totally fine. All good.’” He remembers phoning up good pal Laurie, who serves as an executive producer on both seasons. Laurie said something to the effect of: “‘If you’re standing on set one day and the camera’s on you and I’m standing behind the camera as an exec producer, then I guess we’re doing it.’”

Eventually, after hours-long conversations about how to “crack” a le Carré-esque story that isn’t entirely based on any of the author’s work, season two of The Night Manager was a go, Petrie included. “Eventually, [writer] David Farr was available,” explains the actor. “I think he sat down and said, ‘OK, this is what I would do’ and presented it. There was a general sense of, ‘Oh, OK, this is a story worth telling.’” He also sings Laurie’s praises: “He’s so wise and brilliant about le Carré’s work. As an exec producer, he’s always going to be creatively involved. I think read it and looked at it amongst everyone else and there was a decision: ‘This is the one. I think this is it.’”

The Night Manager is expected to return to screens imminently. Petrie also says the cast is supposed to be filming a third season next year. “David has delivered a Shakespearean tragedy, I think it’s wonderful,” he teases. “This is just based on what I’ve read, but it’s going to be enormous. We’re supposed to be doing a third one next year and I really hope we do, because the people in it and around it are just wonderful.”

With Shakespeare in Love, Hamlet and now a Shakespeare-adjacent season of The Night Manager ahead, Petrie can’t help but think about the bard’s artistic impact on his career so far. “He wrote about all the great themes that run through our emotional lives,” ponders Petrie. “He wrote about power and love and madness and revenge and mortality and jealousy and the fear of God, and he did it pretty well.”

This time around, with his sons all grown up, Petrie’s got the work-life balance a little more figured out. What remains is sheer pride. “In amongst the crash bang of this industry, we raised three well-adjusted, decent human beings,” he beams. “We’ve managed to figure it out, my wife and I, because we are such a team. So the emotion of doing all this is running beautifully high at the moment.”

Hamlet is on at the National’s Lyttelton Theatre until Nov. 22, 2025.