Christopher Isherwood: A singular talent laid bare

Christopher Isherwood is back in vogue. Not that he's ever entirely been out of fashion, of course, thanks to the ongoing success of the various revivals of Cabaret the musical, but the author himself, unencumbered by memories of Weimar nightclub chanteuse Sally Bowles in suspenders and bowler hat, seems to have been firmly rediscovered in the last couple of years.

There was Tom Ford's freshly exfoliated and impeccably dressed screen adaptation of A Single Man, starring an Oscar-nominated and Bafta-winning Colin Firth, as well as the documentary Chris & Don: A Love Story, charting the 30-year-relationship of Isherwood and his partner, the painter Don Bachardy. And more recently we've had Radio 4's Sunday afternoon classic serial Goodbye to Berlin, and the publication of volume two of Isherwood's diaries, covering the 1960s. You could say that Isherwood is on trend for the first time since the Sixties and Seventies, when his message that you could be homosexual and happy was little less than revolutionary.

Now it seems that "Herr Issyvoo", as his Germans hosts were wont to mispronounce his name, is about to find an even wider public – if only because he is being played by none other than the Doctor Who star Matt Smith. In BBC2's one-off drama Christopher and His Kind, based on Isherwood's frank 1976 memoirs of his Berlin years, Smith plays a sexually voracious Isherwood at large amongst the teenage rent boys of Weimar Germany. For the preview screening, a scrum of autograph-hunting Whovians gathered on the pavement outside Bafta in London's Piccadilly; yet it is in this new role that their hero may be embarking on his most eye-opening time-travels yet.

"Hopefully people see me as an actor who can adapt to different roles," Smith tells me. "And I'm very grateful for Doctor Who for giving me the platform to do it – it's one of the favourable things about having a great role like that. But hopefully, watching this, you don't see the Doctor."

Indeed you don't. Interestingly, given that Smith is involved in vigorous, naked gay-sex scenes, there has been no – or very little – prurient press coverage as yet; no homophobic digs or double entendre headlines. You can only imagine the fuss that would have been kicked up had, say, Jon Pertwee played Quentin Crisp back in 1975 – the year after he left Doctor Who. "I don't think it has any bearing whether I'm straight or purple or Bognor Regis or whatever; you can be anything," says Smith. "The point is you pretend and make it all up. I'm just an actor playing a part."

But successful actors pick and choose their parts. Was playing Isherwood, with his pederast's interest in teenage boys, a means of keeping that family favourite, the Doctor, at bay; of not allowing the Time Lord identity to swallow him entirely? "Challenging the perception that I can only be one thing, yes," he says. "I mean, I always want to do varied work that is challenging – and this is a great story."

A story that, in outline at least, will be familiar to anybody who has seen Cabaret, although this Isherwood is a good deal less innocent – a lot more intent on his own pleasure and oblivious to the growing Nazi storm around him – than Michael York's wide-eyed "Brian Roberts" from the 1972 movie.

"It's interesting that someone who sits in a very prim way like this," says Smith, mimicking the Isherwood he had studied on home-movie footage, "was actually very sexual. I went to meet Don [Bachardy], who said to me that one of Christopher's most memorable qualities was the fact that he was very polite... he always made people feel at ease. I wrote it down... 'it's about manners and lust'; and from that I sort of built upwards."

Bachardy, Isherwood's partner until the author's death in 1986, is credited as a consultant on Christopher and His Kind, although the writer, Kevin Elyot (My Night with Reg), says he didn't meet Bachardy while writing his adaptation. Bachardy did, however, invite Smith to visit him at the Californian home he shared with Isherwood, and where he still lives.

"We talked for about an hour about Christopher and what sort of man he was," says Smith. "I hope he doesn't mind me saying this, but I think the overwhelming sensation that I took away was that he had been profoundly in love with him. He said to me that 'the greatest lessons I learnt in life I learnt off Christopher'. Things like that as an actor, they are not literal pieces of information like 'he walks like this or he does this', but you understand the profound insightful nature of the man. I just came away having glimpsed a bit of that somehow."

Smith also came away with the same desk clock, decorated with a dolphin, that was given to Isherwood by his Berlin landlady when he finally left the city after the Nazis came to power in 1933, and which sat on his desk in California as he wrote Christopher and His Kind. "It was quite scary really – we had it under lock and key," says Geoffrey Sax, who directed the drama. "We nearly lost it, but we found it again. It was very kind of Don – and he sent a lovely note to say it was to wish us luck."

Sax had the job of recreating Thirties Berlin in Belfast. "But then a period drama is just as much about what you don't see as what you do see," he says. "You go to any big modern city and you pan left you've got McDonald's, you pan right and you've got Starbucks, and you very much have to restrict your shots. Once you put the swastikas in after the Nazis came to power, that covers a multitude of sins."

Sax also had to distance Christopher and His Kind from the iconic imagery of Liza Minnelli's Sally Bowles, straddling chairs in Bob Fosse's Cabaret.

"Kevin (Elyot) said it really mustn't look like Cabaret. And the real Sally Bowles – Jean Ross – was not a great singer, and the nightclub wasn't as glossy as you see in Cabaret. We were trying to get the songs to tell stories rather than be great performance pieces. With the greatest respect, Immy (Imogen Poots) is not Liza Minnelli – not that we would ever want her to be – so hopefully we went down the more truthful route."

Elyot's central problem, however, was the essentially passive nature of Isherwood – and it's noticeable that the film livens up when Lindsay Duncan (as Isherwood's domineering mother), Imogen Poots (a riotous Sally Bowles) or Toby Jones (a disreputable old queen and Berlin bedsit neighbour called Gerald Hamilton, the Mr Norris in Isherwood's novel Mr Norris Changes Trains) are on screen. Instead, Isherwood was the eternal observer, who wrote in Goodbye to Berlin that, "I am a camera with its shutter open, quite passive, recording, not thinking," – a quote which inspired the Broadway play and film I Am a Camera.

"I remember seeing I Am a Camera when I was a child," says Elyot. "And I saw the stage musical of Cabaret with Judi Dench, and the film, of course, with Liza Minnelli. So I've been familiar with the material for a while, and of course Isherwood is a great icon, and being gay myself, he meant quite a lot.

"At that time a lot of gay men would get married and have children, whereas he went to Berlin to get his hands on some boys. But he was not a joiner; he couldn't quite bring himself to commit. But I think the fact that he was an outsider and enjoyed being an outsider, made him the writer that he was."

'Christopher and His Kind' will screen on Saturday 19 March on BBC2

Isherwood's inspiration: the real Sally Bowles

Nineteen-year-old actress Jean Ross was working as a nightclub singer in Weimar Germany in 1931 when she shared digs with Christopher Isherwood, becoming immortalised as the "divinely decadent" Sally Bowles in Isherwood's 1939 memoirs 'Goodbye to Berlin'. Imogen Poots is the latest of many actresses to play Bowles; others include Julie Harris, in the 1955 film version of 'I Am a Camera', Judi Dench, in the original 1968 West End stage version of 'Cabaret', and, of course, Liza Minnelli, in Bob Fosse's 1972 film of the same.

Unlike the apolitical Bowles, insouciant about the rise of the Nazis, Ross was a lifelong communist – and possibly, it has been suggested, an undercover agent for the Comintern, the international wing of Soviet communism. According to Ross's daughter, the pipe-smoking barrister and crime writer Sarah Caudwell, she never liked her identification with Sally Bowles, thinking it was more closely modelled on Isherwood's flamboyant male friends. Ross was a more talented actress than Bowles (Max Reinhardt cast her in 'Peer Gynt') as well as a writer good enough to earn a living writing for films and newspapers (under the pseudonym 'Peter Porcupine'). Her later life is shrouded in obscurity, but she died in Richmond, Surrey, in 1973, aged 62.