Gregory Doran has lately become a jet-setting director. By the time the less-than-flattering reviews of his Stratford As You Like It appeared last month, he was already in Tokyo to supervise the transfer of his triumphant Royal Shakespeare Company Macbeth. "As the Stratford reviews were faxed through," he says, "I felt like committing hara-kiri. I'd also done five shows in 15 months and felt knackered. Then a fax arrived from the Stratford company simply saying, of the critics, 'Fuck 'em.' "

For Doran As You Like It was a hiccup in a run of success with the RSC. He first worked with the company as an actor in 1987, when he met his partner, Antony Sher - there's an oft-told story of how, playing Solanio, he one night described Sher's Shylock as "the most impenetrable cur that ever slept with [instead of kept with] men." Now Doran, who is in his early 40s, has emerged from Sher's shadow to become a highly prized RSC associate director, often tipped as Adrian Noble's eventual successor - an idea he politely squashes.

Although Doran and Sher have thriving separate careers, they have worked together four times - on a South African Titus Andronicus plus Cyrano de Bergerac, The Winter's Tale and Macbeth for the RSC. Is there ever a danger of he and Sher pre-empting the rehearsal process by sorting out problems at home.

"I don't think so. For a start we're complete opposites. Tony's a pessimist and I'm an optimist. He has a dark, brooding African spirit whereas I have a soft, greyly monotonous English quality. I'm maybe calmer in temperament than he is. But also we're quite rigorous about how we work together. When we did Titus in South Africa we took the work home with us and I began to feel I needed my own space. Now we ration our discussions so that with Macbeth [now on at the Old Vic] I probably talked in advance as much to Harriet Walter as I did to Tony. Having been a spear-carrier at Stratford, I also feel Shakespeare's plays only work when you get a total investment from the whole company."

Some ideas, however, have to start with the director. And one of Doran's most brilliant in Macbeth is to begin the play in pitch darkness. "That evolved," he says, "from directing Peter Shaffer's Black Comedy. I insisted on an absolute blackout for the opening scene which meant turning off all the exit lights. On the Guildford first night I was standing at the back and a man rushed past me in panic saying, 'I've got to get out.' Another night I heard a strange gurgling sound and discovered it was a deaf person suffering from total sensory deprivation. It alerted me to how quickly you could remove people from the simple things they require to keep a sense of equilibrium.

"It's also absolutely right for Macbeth, which taps into all our primal instincts, though initially I made the mistake of having the witches' voices on amplifiers that flew out over the audience. It was too tricksy."

But why does Macbeth so often fail? In my lifetime, I've seen only a handful of successful productions: Trevor Nunn's Other Place version in 1976, Ninagawa's Japanese elegy in 1986 and now Doran's intimate RSC production. "I suspect," he says, "people normally start back to front with it. They start with the theatricality of the witches or the supernatural. The first three or four scenes also go by in a rush of generalised war. In fact, what's happening is absolutely specific. There's an attempted coup d'etat. Maybe Macbeth fights as hard as he does not to re-establish Duncan but to ensure that Cawdor does not become king. But if Cawdor can rebel, why can't he? We felt that the Macbeths seize their opportunity and that the witches are simply observers. I said to Tony one day: imagine someone stops you in the street and predicts you'll win an Oscar. Your agent then phones up to say you've been nominated. Do you rely on a chance prediction or do you get out to Hollywood and do all the promotion? In terms of Macbeth, it's the coincidence of the witches' prophecy rather than the malign purpose of it that strikes one."

If Doran hit the mark dead centre with Macbeth, he is widely perceived to have missed it with As You Like It. But he still believes strongly in the central idea: of Arden as a forest of the mind that becomes an extension of the tapestry Rosalind is working on and that is filled with her own vivacity and imagination. He also laughs off the notion that the rough reviews have lengthened the odds against his ever taking over the RSC.

"Is it my ambition to run the RSC? I don't think so. The job isn't up for grabs so it's not an issue. My sole desire is to direct the plays I want to do. I want to direct an Othello in The Swan with Tony as Iago. And I'd like to do a new version of the Morte d'Arthur for Stratford since I feel it deals with the matter of England."

This summer, however, he's taking a break from the RSC to direct the York Mystery plays in York Minster. Since he was born in Yorkshire, educated at Preston Catholic College and had an uncle who was a Benedectine abbot, he seems the right man for the job. But his own catholicism lapsed when it came into conflict with his sexuality, and anyway he sees the Mysteries as expressions of civic pride rather than openly didactic works. He even relishes the prospect of working with 200 amateur actors. "I was auditioning the other day and a man came up to me and said 'I'm not good at coming in on time and I can't learn lines but I could shout "Crucify him! Crucify him!" if push came to shove.' So he's in. But what I hope to combine is the highly competitive nature of the original Guild shows with Christian iconography. I'm no longer actively religious but, as Sartre said, 'We have a God-shaped hole in our consciousness which we've never learned to fill.' I undoubtedly have one in mine. Most of the time it's filled by Shakespeare who I passionately believe was a Catholic."

Given his lifelong Bardolatry, high intelligence and persuasive temperament, Doran is clearly a strong future contender for the Stratford throne. Whether the gentle but far-from-grey Greg also has the naked, Macbeth-like ambition to take over the toughest job in British theatre is something time alone will reveal.

• Macbeth is at the Young Vic, London SE1 (020-7928 6363), till June 3.