Richard Coyle is sitting on a sofa in London's West End wearing a pair of jeans and trainers with a smart suit jacket, and eating crisps. He has returned in the title role of Michael Grandage's production of Don Carlos, with Derek Jacobi as his tyrant father, which first opened at Sheffield's Crucible Theatre in September. He has also recently played alongside Johnny Depp in the film The Libertine, about the debauched 17th-century poet the Earl of Rochester, due out later this year.
Coyle's transition from playing Jeff Murdoch in the popular BBC2 TV sitcom Coupling - a British version of Friends - the romantic hero in the BBC's Lorna Doone and the weird demon-hunter John Strange in the cult show Strange, has been remarkable. Coyle, who is from Sheffield, has rapidly joined the inner circle of top-class actors and directors. How did he get here so quietly?
"I always knew that I wanted to be on the stage and in films," says Coyle. "Coupling was good for me. It gave me a profile. But I did three series and I just thought that was enough. I didn't want to be Jeff for ever. Those sorts of characters stick. I am always thinking long term. I wanted to back away from television. I wanted to concentrate on stage and films. I went away to clear my head - to Mexico, US, China, Mongolia and Russia for six months."
But Coyle had already made his stage debut in 2002, in Peter Gill's hit The York Realist at the Royal Court, before landing the part as Gwyneth Paltrow's co-star in Proof - a gritty saga about mathematicians - directed by John Madden at the Donmar Warehouse the same year.
"Gwynnie and I escaped the paparazzi through the back fire doors of the Donmar, but the photographers always ignored me," recalls Coyle. "I thought Gwynnie would get star treatment in rehearsals too. I thought it would be all about her. You know, that the director would give her all the attention. But that didn't happen. It was a very democratic process. She worked very hard. It was also intimidating for her because it was her London stage debut. There were times when she was very scared about what she had let herself in for, especially with the critics here being notoriously harsh. But she is just an ordinary person."
By the time Coyle returned from his travels in 2003, he was already booked in to star in Patrick Marber's sassy re-working of Strindberg's 1888 classic After Miss Julie. He also filmed Gunpowder, Treason and Plot alongside Robert Carlyle. Now, having topped up on a few weeks of rehearsals, he is ready to play Don Carlos, who is passionately in love with Elizabeth, the French princess, when his father, King Philip II of Spain (Derek Jacobi) steals her for himself.
"I never planned on being an actor," says Coyle. His father was a builder, and he has four brothers. "I am the only actor. There is no showbiz in my family." It was not until he went to York University (1991-4) to study politics that he got involved in the student drama society. After getting a place at Bristol Old Vic Theatre School, he deferred it for a year while he raised enough money to study. "During this time, I got a part as an extra in Franco Zeffirelli's film Jane Eyre with Charlotte Gainsbourg and William Hurt. They were filming in Derbyshire, near where I am from, and they were holding auditions for extras at the local post office. So I went along and got a part." Did he say anything? "Not originally, but I was making a nuisance of myself telling everyone that I was going to drama school. Got any tips? That sort of thing.
"I was being really annoying. I started speaking to the director, Franco Zeffirelli. He gave me a line - and I shouted, 'Mr Rochester, your house is on fire!' running across a field in a shepherd's tunic, chasing after William Hurt. I was all over that film. They kept giving me different costumes. I am hailing a coach; a footman in the hall; cleaning a horse. I am like this recycled extra. Then I spent three months writing thousands of letters to people, begging for money to go to drama school. Eventually I got the money."
Don Carlos is the second production in which Coyle has been directed by the Donmar's artistic director, Michael Grandage. "I respond to Michael. There is a connection with him that I have not really had before," says Coyle. "He knows my abilities and my weaknesses almost better than I do. He is incredibly insightful. I love the way he can gently massage your ego in rehearsal - which is very important - before breaking it down slightly because he has to. It is a very difficult trick to pull off. He knows how to get the best out of his actors. He does not like to do a read through of a play. He likes to get straight on with it."
Coyle says that when he first read the script for Don Carlos, he didn't know where to begin with the character. "I was lost. It is a difficult role. He is a complicated character. It is an even more complicated journey; a real roller-coaster journey.
"I turned up at rehearsals wanting to play the real Don Carlos - this guy with a hump and a lisp, a little bit twisted - and Michael said, 'No! We must like him!' In real life, Don Carlos was a nasty piece of work. But Michael knew what we needed to do. He wasn't having it."
Coyle lives in north London with his wife, the actress Georgia Mackenzie, whom he met on the set of ITV's Up Rising. "We played a couple who get together at the same time that we got together in real life," says Coyle. "It is great. Whenever we need a potted history of our relationship, we have something to watch on the video."
What is his perfect part? "I don't have one particular part, but I always like characters that are a little dark and twisted - parts that are slightly sinister. It is more interesting." He really wants to play the more unusual parts in Shakespeare, such as King John, Cymbeline, Pericles, Timon of Athens. "I love being other people," he says. "If you can touch others, it is a huge thing to be able to do."
'Don Carlos', Gielgud Theatre, Shaftesbury Avenue, London W1 (0870 890 1105) previewing from 28 January; opens for a 12-week run on 3 FebruaryReuse content