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Relaxing in a black leather armchair in his tiny but surprisingly homey dressing room at the Bernard B. Jacobs Theatre, British actor Michael Sheen, currently burning up the Broadway boards in Frost/Nixon, exhibits the easygoing charm and lively eloquence of a man whose time has finally come.

Already considered one of Britain's most respected actors, having delivered acclaimed performances in Caligula, Amadeus, Peer Gynt and Romeo and Juliet on various international stages, the 38-year-old Sheen arrives brandishing a fistful of critical superlatives, including this pressure cooker from London's Observer: "the most exciting actor of his generation."

Now Sheen's star is steadily rising on this side of the pond. Filmgoers no doubt remember Sheen's multi-layered turn as former British prime minister Tony Blair in last year's Oscar-nominated film "The Queen." And he's had memorable supporting parts in movies like "Laws of Attraction," "Bright Young Things" and "Wilde." Then there's Frost/Nixon, which re-creates the famous 1977 showdown between jet-setting British journalist David Frost and a post-Watergate Richard Nixon (played by 2007 Best Actor in a Play Tony winner Frank Langella). To top it off, Sheen will begin shooting the film version of the play, directed by Ron Howard, at the end of the summer.

At this moment, though, Sheen is busy talking about his recent penchant for playing real-life characters. In addition to his role in "The Queen," the actor, who has a daughter with British beauty Kate Beckinsale, has brought famous figures to life in the British TV movie "The Deal" (in which he also played Blair) and his current gig, in which Frost — a talk show host and notorious playboy who was considered something of a journalistic lightweight at the time — gets Nixon to apologize to the American people for his role in Watergate. "I think playing a real-life person brings a challenge over and above what you have to do with a fictional character — the extra work you have to do and how specific you have to be about the research," says Sheen, a brightly colored, pop art silkscreen of Frost hanging above his head. "You have all the normal things that you have to deal with when you play a character, where you have to tell the story and try to work out what the writer is intending. But you also have a responsibility to this actual person, in terms of trying to find out what they're all about."

Impersonation of Frost is obviously part of the performance, but Sheen is flummoxed as to why that's become such a dirty word. "I read reviews where critics write, 'So-and-so plays this character without resorting to impersonation' — as if impersonation is a really bad thing or it's cheating somehow. If you're playing a real person, you've got to be like him. That's the whole point. You don't have free reign to do whatever you want. I suppose impersonation means just doing the stuff on the exterior. But what's happening on the surface is often an expression of what's going on underneath. So in some ways, the closer you get on the outside, the more that can help bring out what's going on under the surface. The two should be connected, really."

To research the part, Sheen dug deep into Frost's life and times. But playwright Peter Morgan (who also penned the screenplays for "The Queen" and "The Deal") urged him not to meet with Frost before creating the role. "It's a warts-and-all portrayal," Sheen explains. "And because David is such a charming man and a lovely guy, Peter was worried that if I got to know him whilst I was working on it, then I might shy away from certain aspects of the character."

When Sheen finally did meet the man he's been playing, after the show opened at the Donmar Warehouse in London last summer, he asked Frost if it was peculiar watching himself up onstage. To which Frost replied in his distinct accent, "'In the words of Yogi Berra, it was like déjà vu all over again,'" recalls Sheen with a laugh. "But he was very supportive and very generous."

Frost's approval was particularly gratifying since the play takes a number of liberties with the historical events leading up to the face-off between the two ambitious men, who are both in the throes of a professional crisis. The interviews became a stark reminder of the power of television — a medium in which Nixon was visibly uncomfortable and Frost was a natural. "In order to make the piece work, you have to sort of underestimate Frost for a long time and not think that he's going to succeed. So there are things in the play that have been exaggerated or made up entirely."

One of the invented scenes, written to increase the dramatic stakes of the play, is a late-night phone call between Frost and a deliriously drunk Nixon on the night before their final interview. "It never actually happened," Sheen says of the powerful scene. "It's Peter's interpretation of what was going on psychologically and emotionally between these two men at the time. What that scene explores and expresses about them is true."

After the Broadway run of Frost/Nixon concludes in mid-August, Sheen and Langella will re-create their roles for the big screen. Then Sheen is expected to re-team with Morgan and "Queen" director Stephen Frears to tackle another real-life character: the legendary English soccer coach Brian Clough in the film version of the novel "The Damned United."

Though Hollywood may come calling, don't expect Sheen to give up the stage anytime soon. "The more film work that I do, the more I enjoy that world," he says. "But there is nothing like walking out onto a stage and having 1,500 people there watching you, and playing that game with an audience. There is nothing quite like it."