Blazer, Bottega Veneta ($2,180). Barneys New York, Copley Place, 617-385-3300. T-shirt, Forty Seven ($40). Yawkey Way Store, 19 Yawkey Way, 617-421-8686 . Jeans, A.P.C. ($210). Barneys New York, Copley Place, 617-385-3300 . Watch, Girard-Perregaux ($14,900). Yuri’s Watches, 142 Newbury St., 617-536-8895. Boots, Chippewa Boots ($140). David’s Shoes on First, 75 First St., Cambridge, 617-354-3730. Genuine game-used bat, courtesy of the Red Sox.

After nearly three decades as an actor, John Slattery can look back on numerous honors, including two ensemble Screen Actors Guild Awards and four Emmy nominations. But the one that surprised him most came from the toymaker Mattel, in the form of a Barbie doll made to his likeness—or rather, that of Roger Sterling, the cocky and sodden executive he plays on the TV series Mad Men. His chiseled good looks, silver hair, and athletic physique, clothed in a sleek 1960s suit, are now captured in vinyl. Growing up in Newton and then Wellesley in the '60s, Slattery might have fantasized about ending up on a baseball card, as a player for his beloved Red Sox. But he couldn't have imagined he would enter the national consciousness on a television series about martini-soaked advertising executives, whose cutthroat antics would make even Fenway Park's most competitive gamesmanship look like child's play. Landing the Sterling role is a source of wonderment for Slattery, who marvels at how he "got lucky enough to be part of Mad Men."

But tenacity has had as much to do with Slattery's success as luck. He takes the glare of his new-found fame in stride, thanks to the work ethic his parents instilled in him, an actress-wife who keeps him grounded, and years of laboring in relative obscurity. But in a profession often unwelcoming to the late bloomer, Slattery, on the cusp of 50, is just hitting his stride.

"John is one of the great, great actors of his generation," says Sarah Jessica Parker, who has known him since the early '90s. She adds that she "begged" the producers of Sex and the City to cast him opposite her in the role of Bill Kelley, the suave politician with a kinky habit. "His acting appears effortless, which, of course, it's not," she says. "He's not a showoff. He really cares about the work." The South Boston-born playwright David Lindsay-Abaire lobbied for the actor to costar with Cynthia Nixon in Rabbit Hole, which won the 2007 Pulitzer Prize for Drama. "John played a golden boy whose life is blown apart," says Abaire. "That emotion, anguish, and confusion is tricky to maneuver, yet he played it beautifully. He can be likable while playing the most caddish of characters. You can't pin him down, and that makes him eminently watchable."

For Slattery, his extraordinary range of roles—smooth politician, ambitious roué, tortured architect, drug-addled army vet, betrayed husband— is simply a part of the job description. He is drawn to characters who are mired in moral ambiguity, constrained by the circumstances they are born into or thrust into by some untoward incident. He notes that Roger Sterling may appear to have all the answers with his devilmay- care swagger. But no one can ignore the shuddering fault lines beneath the cool, sleek landscape of Mad Men. And, he adds, "There's nothing funnier than someone who thinks he has it right, who is so confident, and who really has his head up his ass."

Slattery's friends say there's no chance he has his own head up his aforementioned. Parker points out that her good friend is wise enough to know where the "land mines [of fame] are and how to avoid them." Slattery is also mordantly aware that an actor's life is always a process of reinvention, of moving forward but never really arriving, no matter what his personal Q rating might be. "It's an actor's fantasy to be in my position," says Slattery, who, prior to Mad Men, played occasional featured roles in movies (Mona Lisa Smile, Flags of Our Fathers) and guest shots on TV series (Will & Grace, Desperate Housewives). "You work hard to get to a certain place, then you get there, and it's not quite what you expected. That implies a certain dissatisfaction, which isn't exactly right, but failure can be a lot easier to rationalize than success. Maybe it's an Irish thing."

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