Roger Allam takes up a lot less room than you'd expect. This is no bad thing, as we are meeting in a break from rehearsals in the National Theatre's tiniest cubbyhole. Still, it's surprising, when you consider some of his larger-than-life incarnations – as a self-satisfied Casanova in Boeing-Boeing, as a droll Abanazar in Aladdin and, in the blockbuster Speed Racer, as the oleaginous fat cat villain. As he tucks himself up on the sofa, he seems a little deflated; diffident, even.
But then he opens his mouth. The 54-year-old actor is undeniably portly, but it is his voice, as rich and plummy as mature fruit cake, that lends Allam his scene-stealing heft. Even off-stage, Allam rumbles, guffaws, purrs and snorts in a way that makes it hard to imagine him doing anything but treading the boards for a living (indeed, he also considered opera for a job). Which brings us to his latest role, playing the impresario Max Reinhardt in Michael Frayn's new play, Afterlife.
Born in Vienna in 1873, Reinhardt devoted his life to the stage, directing some 340 productions and building or restoring 13 theatres across Austria and Germany. At his zenith, just before the First World War, he was said to be the third most popular personality in Germany – after the Kaiser and Count Zeppelin – attracting enormous audiences to his touring productions, which had casts of thousands and epic, acre-spanning sets. But for all the spectacle and lavish parties, Reinhardt's is a sad tale. Frayn focuses on his desperate attempts to stage his annual play, Everyman, at the Salzburg Festival in the face of the encroaching storm cloud of Nazi rule. In 1938, when Hitler absorbed Austria into the German Reich, the Jewish impresario was forced into penniless exile in America.
"There's a sense in which he didn't fully engage or even exist outside of theatre," says Allam. "Where he most fully lived was while he was rehearsing, or putting on a show, or thinking about putting on a show." Does Allam share the obsession? "It's something I recognise, certainly. As soon as you have two small children, they take up a lot of time and energy. But one of the satisfying things about performing a play is you know for that piece of time exactly what you're going to be doing. Your life has a physical pattern. There's something about the odd, repetitious nature of it that I find hugely relaxing. All the problems of life are taken care of for that bit of time."
Allam's theatre roles have ranged from the serious – Willy Brandt in Frayn's Democracy, Hitler in David Edgar's Albert Speer – to the starry – opposite Gillian Anderson in What the Night Was For – to the silly, in Aladdin. After studying drama at Manchester University, he joined the feminist troupe Monstrous Regiment, then moved to the RSC in 1981, where he created the role of Javert in Les Misérables. Another musical outing – as a shriekingly camp Captain in drag in Privates on Parade at the Donmar – earned him an Olivier Award in 2001.
He ascribes his tendency to flit between roles to one of his earliest theatrical memories, at Christ's Hospital School in Sussex. "There was a book in the library which was a series of interviews with Gielgud, Olivier and Richardson, all of that generation. For each interview, there were little pictures of them playing different parts in their early career. Beards, monocles, different noses, wigs... I thought, 'Oh god, fantastic, fabulous'." Allam made his stage debut in his last year at school, as Sir Toby Belch in Twelfth Night. "I based my look on one of those pictures of Olivier. I had a false nose, a bald wig, a wig, padding – the works."
Allam has cropped up on screen, in The Thick of It, The Wind that Shakes the Barley and The Queen, not to mention his burgeoning relationship with The Matrix siblings, Andy and Larry Wachowski. After working with him on a small role as a fascist television presenter in V for Vendetta, they gave him top billing as Royalton, the jowly face of corporate evil in Speed Racer. "They like British actors. I suppose there's a particular kind of efficiency about coming from a theatre tradition. You don't make a fuss, and you're cheap." Did he enjoy the Hollywood experience? "It was a ball. I thought the film was great. So did my son. I now can't get away from it – Speed Racer pyjamas and all that..." says Allam, who lives in south-west London with his actress wife, Rebecca Saire, and their two young sons.
The film could gain Allam the kind of fame that has thus far eluded him. Even the homepage of his website declares, "Roger Allam is one of those actors who seems to be in a lot of things but no one really seems to know who he is." He doesn't seem bothered, though. "I wouldn't enjoy the prospect of not being able to go round my local supermarket. I'd love to do more film but I've never had the willpower that someone like Tom Wilkinson had at a certain stage in his career to say, 'Right, that's it, I'm not doing any more theatre, I'm concentrating on film.' One of the great things about doing a play, repeating it over and over again, is that you can practise," he grins sardonically. "And you can get really quite good at it for a while."
'Afterlife', to 16 August, continuing in rep, National Theatre, London, SE1 (020 7452 3000)