GAME OF Thrones regular Owen Teale will film the fifth season of the swords, sex and sandals drama later this year.

More immediately, you should put all thoughts of Teale's baddie Ser Alliser to one side, focusing instead on the Welshman's appearance on a York stage from Tuesday in the "Richard Burton role" in Clwyd Theatr Cymru's tour of Under Milk Wood.

Artistic director Terry Hands's touring production is marking both the centenary of Dylan Thomas's birth and the 60th anniversary of his play and poem's British premiere as a BBC radio play in 1954.

The setting is Llareggub, an imaginary small Welsh town by the sea, where you will meet blind Captain Cat, Mog Edwards and his sweetheart, Miss Price, Sinbad Sailor, Dai Bread, Polly Garter, Nogood Boyo and Lord Cut Glass. Thomas explores their lives, hopes and thoughts "in the dreams of a night and the rhythm of a day" as his story takes a walk along Coronation Street, Cockle Row and Donkey Street, down to the little fishing harbour and back to Milk Wood.

The anniversary tour opened in Clwyd Theatr's home of Mold and its English run begins at York Theatre Royal. An American tour will follow next year.

"I'd say what makes it timeless is the poetry," says narrator Owen.

"When you need poetry is to explain a complicated emotional arc; to heighten drama; to get close to human nature and our love of childhood; to capture character and to make those characters play. That's the enduring appeal; it's about play.

"They don't know they're being watched, so there's a strong feeling of lust, and above all they have a relationship with time, where they don't want to grow up and have never reconciled themselves with the loss of childhood and yet know they will all die. Ironically Thomas himself was dead by the age of 39."

Under Milk Wood has a "life of its own," suggests Owen.

"That's what this production brings out enormously. Word goes around that seeing this play is like going to a party; people take time out of their lives to have a great party with Dylan Thomas. We had to put on an extra show at Cardiff with people wanting to return for that 'extra hit'."

Hands's production has a distinctive circular set that "opens out like a clam or almost like a compact mirror". "What it reveals is the town within, where a day in the life of the townsfolk starts in the middle of the night, in their dreams, so Thomas wastes no time in getting inside their heads to show what they're dreaming of," says Owen.

The set is completed by chairs in the middle. Into this scene steps Owen's character, the gatekeeper, or First Voice as he is known, who narrates the events of the night and day as he leads the cast of 11.

"I set it all up, trying to recall what happened, going back to a place that you long for and then it drives you mad again," he says. "It's like travelling the country with a large, slightly dysfunctional family; and the audience witness that as much as they witness the characters."

Owen, 52, has a long association with Under Milk Wood that stretches back to his school days, although Clwyd Theatr's show gives him his first Thomas role in a career that has included a Tony Award for best actor in Ibsen's A Doll's House on Broadway.

"I did Under Milk Wood at school, It was the first thing I learned, when I was ten, and I did Mog Edwards, the draper," he says. "That was at Cornelly, Port Talbot, but though I went to school there, I was born in Swansea, next Cwmdonkin Park, where Dylan Thomas spent his childhood."

Over the years, his appreciation of Thomas's language has grown.

"It's a wonderful thing; I now realise it's a form of English that is entirely its own. It's Welsh English, as unique as James Joyce's Ulysses in Ireland," says Owen. "It's the rhythm; the love of words. Sometimes, he'll think, 'why use one perfect adjective, when you can use seven?', especially if they're alliterative.

"It's stood the test of time because it's heightened language where you're going towards something that is almost Shakespearean, and it's my job to make it as natural as possible. That's my great challenge, not to make it seem like I'm reading from a lectern but that I'm speaking off the cuff."

Once Under Milk Wood's tour winds to a close, Owen will start filming this summer for the next season of Game Of Thrones, whose fourth series is now showing on Sky Atlantic.

"My bits are filmed in Belfast, always in the rain, like it was for all the filming last year," he says.

"I play this sergeant of arms on a 400ft wall of ice at the edge of the known world. It's like a foreign legion, where they take a vow of celibacy, and my character Ser Alliser is such a bully, making every recruit's life a nightmare."

Owen loves the role.

"Ser Alliser has utter disdain and contempt for people's feelings and great language to show that disdain," he says.

The world loves the show, including China and Russia. "It's now the most downloaded show of all, because it's telling the history of the world, with all the epic power struggles and great, great stories of empire – and it gets away with murder with all the sexual content as it's set in mediaeval times!"

Clwyd Theatr Cymru presents Dylan Thomas's Under Milk Wood at York Theatre Royal, Tuesday to Saturday, 7.30pmplus 2pm, Thursday, and 2.30pm, Saturday. Box office: 01904 623568 or at yorktheatreroyal.co.uk