Walking past a copse with an abandoned caravan on a particularly derelict stretch of the Norfolk coast this summer, a friend commented, "how very Jerusalem". By which he meant, obviously, not the holy city, but the wooded patch of hinterland in south-west England brought so pungently to life in Jez Butterworth's smash-hit play. It's been a long time since a play had the power to take on its own life as an adjective. Jerusalem, with Mark Rylance as its modern-day high priest of anarchy, taking on Kennet and Avon council on St George's Day in an impoverished rural England still haunted by its ancient myths, has somehow slyly but indelibly wormed its way into our national consciousness.
Sitting in a Soho café on the eve of Jerusalem's second West End run, Butterworth today looks every inch the major player – a far cry from the man who he admits used to convince himself that the creative muse could be found down the pub. Jerusalem added a Tony to its clutch of awards during its recent Broadway run; Sam Mendes has just called about an exciting new project that Butterworth is not allowed to talk about (but can't help himself anyway); there are more plays in the pipeline and he has even just secured himself a permanent base in London (although his main home remains a pig farm in Wiltshire with his wife, Gilly, and his two daughters, aged five and two). Yet it is Jerusalem that will perhaps remain his greatest achievement – an intoxicating portrait of a nation almost subliminally trapped between the forces of old and new, chaos and officialdom, and steeped in an atavistic sense of rebellion and magic.
"When I wrote the first draft, in 2004, the problem with the play was that, actually, it was trying to be state-of-the-nation," he says, big and beardy with a beret perched improbably on his head. "It didn't have anything else. Now, looking back, I've got a lot more of a sense of why it came about the way it eventually did [he finally finished it after an intensive short burst in 2008]. I can now see things in it that were clearly possessing me at the time. I wasn't really trying to write about England particularly, although obviously I was writing about a certain community. But I was really trying to summon up an anxiety that I had about change. Not social change. I don't give a shit about social change. Personal change. Parenthood."
Playwriting has always involved for Butterworth "an unpalatable amount of self revelation". He describes growing up in St Albans in a house "where change was illegal" and suggests that, as a result, it's his own conflicted relationship with change that bubbles away under the surface of all his work. He describes the process of writing as simple, and terrifying. "It's about how much you are willing to bet of yourself. And that involves placing yourself in dangerous places. I can't overstress how personally calamitous those sort of risks can be – it's sent me mad on occasion, actually. But there is a wonderful freefall that comes when you are completely unafraid of what's going to be revealed. I can't put it clearer than that. It's a complete abandonment to the process."
He first moved to Wiltshire in his late 20s. "I was there for two or three years while writing Mojo [his 1995 debut, a gangster comedy, set in Soho] so not only had I already experienced the countryside when it came to writing Jerusalem, but I'd been dirt poor in it. We were living in Pewsey, and I remember one January going out with £1 to my name to the pub, and winning £10 on the machines, which meant we could heat the house for a week. So I never had any illusions about the countryside being some sort of bucolic paradise."
Undeterred, he moved back again for good in 2006. The visceral rigour of working the land started to bleed into his work. "Around that time I wrote The Winterling [another slice of gangster noir, this time set on Dartmoor] – a play that's soaked in death, blood and guts," he says. "I look at that play now and realise: that's someone isolated in the countryside and a bit bruised."
Try and pin Butterworth down on just what he thinks about Jerusalem, with its allusions to Shakespeare, ley lines, folklore and William Blake, and its earthy sense of requiem for an ancient, vanished land, and he becomes positively mystical. He's not that interested in ideas of nationhood, or identity. He's not concerned about what the play might have to say about violence, or whether any link can be drawn between, say, the alienation and disaffection of Johnny "Rooster" Byron – the amoral, drug-dealing waster with the soul of a poet and the spirit of a revolutionary – and the recent nationwide riots. What he is interested in is something much deeper, something he compares to Lorca's idea of Duende, a profound melancholia that Lorca himself described as "the spirit of the earth", and which for Butterworth is the closest he gets to a personal muse.
"What I got from the countryside is that unnameable sadness that, for me, gets to the heart of anything worth singing or writing about," he says. "In England, myth has never been political, like it is in, say, America, but part of the imagination. And like all mythologies it's all a question of how good we are at accessing them. I do notice that I spend a lot of all my time steeped in different forms of myth, such as English folk music for example, not really studying it necessarily but just trying to experience it so I can recall it later. And for me, theatre is there to bring out these things in a ritual form which allows the audience to share them and look at them and hopefully something will change."
He describes himself as determinedly apolitical. "I grew up in a household that was very left wing," he says. "My father got a trade union scholarship to Oxford; he lived and breathed politics; he was always watching current-affairs programmes. But I have a five-year-old child's attitude towards the news. Mainly, that it absolutely turns me off. I don't read newspapers in that way. I'm not interested in what's going on." He stops and grins. "But that's not to say I'm not paying attention. I'm just paying attention to other things."
'Jerusalem', Apollo Theatre, London W1 (020 7492 1548) to 14 JanuaryReuse content