Making his mark: Mark Rylance the West End wonder

'Ah-buck-buck-buck-buck' Mark Rylance is flapping his elbows and strutting like a chicken in the middle of the street. He's demonstrating how, every night, the hens that appeared on stage with him in

For Rylance, who turned 50 in January, these 'feel like auspicious times'. He's long been considered one of our finest classical actors for his work at the RSC and as the founding artistic director of Shakespeare's Globe. As Al Pacino once said, he plays Shakespeare 'like it was written for him the night before'. Lately, contemporary roles have brought his genius to a wider public – 2008's trolley-dolly farce Boeing-Boeing, and Jerusalem, about a drug-dealing pied piper. Next, he will appear at the Comedy Theatre in La Bête with Joanna Lumley, playing the naff troubadour Valere, whom he likens to 'the voiceover of Come Dine With Me'.

When I meet him outside his rehearsal room in Southwark, he is wearing a natty little hat and a small 'alternative' hoop through one ear. He played Peter Pan in 1983­ – not a dry eye in the house, apparently – and almost could today. He has lost the bulk he gained for Jerusalem, but still has that mystical gift of the gab. His voice is beautiful, resonant and slightly Anglo-American, belonging to a profession more than a country.

'I celebrate all the eight folk festivals of the year,' he tells me softly. 'Midsummer, midwinter, the equinox, the fire festival and the others in between. They're very helpful to my year. There's the sense of the wheel turning, a sense of thanksgiving for where we are, for the gifts we have. I celebrate them with friends, at a restaurant, eating, drinking, laughing, and offering beauty to the gods.' How does one do that? 'With words, songs, thoughts, colours, fruits and flowers.' I imagine him placing a
pineapple under a tree for Pan. 'We're as much part of nature as these stones are,' he says, gesturing to the cobbles underfoot.

His favourite place to learn lines is down by the Thames: 'Tamesis, the black mother, the dark, chaotic root of life in the city that's gathered all this life around it' He climbs over the barrier and gets up on to a 'big concrete block in the river, looking over at the National, imagining Elizabethan life and watching life as it is now'. He remembers being taken there for the first time by Nigel Hawthorne, in between matinees of Tartuffe at the Barbican, and talking to the 'mudlarks', the people digging for treasure on the river's shore. 'I love the way she [The Thames] sifts and sorts the rubbish out by weight'

Polytheism comes naturally to him. Raised in Milwaukee by British parents (teachers who emigrated for work), he was brought up Catholic and Anglican, to please both sides of the family. 'We went to different churches on alternate weeks, and on Christmas and Easter, we would have to go twice.' It sounds confusing. 'My experience of church was always of translating – oh, this must mean that. And ritual. My mother would put on Christmas pageants, with candles, that were just magical.'

He got into spiritualism in the late 1980s, around the time he met his wife, the
composer and musician Claire van Kampen, when they were working on The Wandering Jew at the National Theatre. The two left to form their own company, Phoebus Cart, and took The Tempest touring British ley lines. Immersing himself in Shakespeare led him to esoteric schools of thought such as Kabbalism and what he refers to as cosmic geography. In southeast London he and his wife brought up her two daughters from a previous marriage, Juliet and Natasha. 'We would have loved to have had children together, but it wasn't possible,' he has said.

Juliet is now starring in Sam Mendes' As You Like It at The Old Vic, opposite Christian Carmargo (of Heroes), her real-life husband. Rylance refers to her as 'my daughter', and she to him as 'Dad' and despite being close to her biological father, the architect Chris Perret, she took Rylance's surname. 'I'm very proud,' he says.

There's also a worldly side to him. After Jerusalem, on stage at the Apollo, he would stay up into the early hours playing poker with the stagehands. As an actor-manager he got the Shakespeare's Globe off the ground and ran it for ten years. (His all-male Twelfth Night, in which he played Olivia, was a high point.) You can't do that without business sense. The only equivalent career that comes to mind is Kenneth Branagh's, his contemporary at RADA.

Arriving from America, Rylance found it 'claustrophobic' at RADA and has only one friend from his three years there, Michele Wade, who runs the Soho patisserie Maison Bertaux. He had 'a big falling out' with his other best friend, 'an older actor, a great inspiration and a very troubled person; I'm drawn to troubled people'. They founded a theatre company together, The London Theatre of the Imagination, and Rylance lost £8,000; they played Iago and Othello, which didn't help. 'The trust was gone and our paths split,' he says. 'I'm often the egg-breaker. This could be bad for me in early companies. When I feel there's a truth that's not being spoken, I find that hard to deal with. I'm better now, more patient, but in the past I'd be explosive.'

In the 1980s he had a hedonistic phase, a dalliance with drink and drugs. 'I found the more interesting people were dropping out and finding an alternative way of being. I was lucky enough to be around good people and it didn't get so excessive that I damaged myself. It was something I had to do. I'd been working very hard on theatre since I was 13, 14, and I needed some space, something to calm me down. I do have a need for wildness.'