THE last time David Hare brought a brand new play to Edinburgh was almost half a century ago, when he was in his early 20s. That was with Portable Theatre, the collective formed by Hare and fellow young radicals in the heat of the revolutionary possibilities fired by the student rebellions of 1968. Now, aged 72, Hare has just opened his epic reimagining of Henrik Ibsen’s Peer Gynt at the National Theatre of Great Britain in London prior to an Edinburgh International Festival run. This sees James McArdle leading a mainly Scots cast as the youthful fantasist who embarks on a series of adventures before his older self is forced to reconnect with everything he left behind.

“It’s a massive undertaking,” says Hare. “With something like this you either go minimalist or maximalist, and we’ve gone maximalist. It’s a bit of a monster, but I think we’ve tamed it.”

Hare begins his new version of the play in 21st century Scotland, with the action moving from Dunoon to Florida, Egypt, the Bay of Biscay and beyond.

“What appealed to me about it is that Peter Gynt is a fabulist and a storyteller, and in these days of the internet and social media, everyone can invent their own story and access their own journey.”

Much of Hare’s new take on things comes from a personal root.

“My mother was from Paisley,” he says, “and we used to go to Scotland all the time, but I ended up writing in this English voice, so writing this play in a Scottish voice, and in my mother’s accent, was incredibly liberating.”

Hare recognises elements of himself as well in the play’s title character.

“I think I was probably a lonely child, and I did fantasise,’ he says. “I spent all the time thinking about the life I wanted to live, but I also think I was hit by a dose of reality much earlier than Peter Gynt. The fascination in the play is the stages he goes through. He becomes a capitalist, and even in the 19th century Ibsen was saying that the effect of capitalism was that we would become more alone. He predicted the whole emphasis today on going it alone, and on self-fulfilment, self-promotion and self-absorption.”

Hare has embarked on quite a journey of his own over the last half century. His beginnings with Portable saw him direct compendiums of Kafka and Strindberg before presenting plays of his own or his contemporaries at Edinburgh’s long-lost Pool lunchtime theatre and the Traverse.

In an act of collectivism typifying the times, Hare teamed up with contemporaries Howard Brenton, Snoo Wilson, Stephen Poliakoff, Trevor Griffiths, Brian Clark and Hugh Stottart to co-write Lay By, which explored attitudes to pornography and sexual violence in society. Even in 1971, the show’s provocative material shocked many.

“There were a whole lot of shocking plays we used to do late at night that caused a lot of furore,” says Hare of his youthful endeavours. “There were two sides to the fringe movement. One side was Bacchanalian, and was made up of those who had this hippy ideal of being free and being able to indulge yourself, who believed that having a good time could change society, and that somehow because of these freedoms, society could be mysteriously improved. Then there was another side who believed that political action could change things.”

When Hare’s play, Slag, was seen at the Royal Court, it set him on a path that would see him become a major presence in British theatre. Plays such as Plenty appeared in the West End and on Broadway, while a relationship with the National Theatre saw the likes of The Secret Rapture investigate the personal and the political in the thick of Thatcherism. A trilogy – Racing Demon, Murmuring Judges and The Absence of War – dissected the Church of England, the British judiciary and a Labour Party in freefall.

More recently, South Downs was a response to Terence Rattigan’s The Browning Version, while The Moderate Soprano looked at John Christie, the founder of Glyndebourne Opera and his romance and marriage with singer Audrey Mildmay. In 2018, Hare’s seventeenth new play for the National, I’m Not Running, looked at the two separate paths taken by would-be leaders of the Labour Party.

“This doesn’t relate to Peter Gynt directly,” Hare says, “but there have been immense social improvements since the 1960s. “People were extremely repressive and judgemental, and people killed thought because they weren’t allowed to be who they were. Of course, there are all these awful things going on in America and elsewhere, but I think we’re much more socially empowered that we were then. It’s why Brexit’s nostalgia for the 1950s doesn’t wash with me.”

In this respect, Hare’s play sounds like a thoroughly modern Peter Gynt.

“The important thing is to knock on the head this idea that a spiritual journey is a journey you take alone,” he says. “I think that has become a fashionable idea in the 21st century, that you can grow your own garden, but I don’t think that’s the case. In my life, my garden has grown through sharing things with other people, and anything important in it has come from that. I don’t think the idea of being rich, famous and alone is a good way to be.”

Peter Gynt runs at the Olivier Theatre at the National Theatre of Great Britain, London until July 16, then opens at Edinburgh International Festival at the Festival Theatre, August 1-9, 7-10.45pm, August 4, 7, 9, 10, 12.30-4.15pm, before returning to the Olivier Theatre at the National Theatre of Great Britain, London from August 16-October 8.