WHEN John Durnin decided to programme The Ruling Class as part of Pitlochry Festival Theatre's summer season, early read-throughs were greeted very differently by various members of his cast. Peter Barnes' rarely-revived 1968 critique of a nation divided by sanity, madness and the aristocracy, focuses explicitly on a world riven by social schisms. The split here, however, depended largely on age.

“For the younger cast members, discovering the work of this strange and most forgotten of playwrights was a completely new experience,” says Durnin, who has been artistic director of PFT since 2003. “Whereas for the older members of the cast, who already knew the play and Barnes' work, it was a rediscovery of his unique use of language and theatricality.”

The Ruling Class charts the accidental rise of Jack Gurney, who becomes the fourteenth Earl of Gurney, despite being a long-term resident in a psychiatric hospital. Gurney believes himself to be Jesus Christ after developing delusions of grandeur while at boarding school. The play was first produced at Nottingham Playhouse, where the leading theatre critic of the time, Harold Hobson, described it as one of the best debut works of its generation, and noted Barnes as one of the most distinctive and profound voices of his era.

Barnes had actually had two plays produced previously; The Time of the Barracudas in 1963, and Sclerosis in 1965. It was The Ruling Class, however, which captured the public and critical imagination. Its heady mix of anti-naturalism and audacious critique of the British establishment also piqued the interest of maverick actor and some-time hellraiser Peter O'Toole, who went on to play Jack in the production's west end run. O'Toole also acquired the film rights, and was nominated for an Oscar for his performance in Peter Medak's 1972 big screen version.

The play shared the 1968 John Whiting Award with Edward Bond's Narrow Road to the Deep North, and in 1969 led to Barnes receiving the Charles Wintour Award for Most Promising Playwright at the Evening Standard Awards. The award came the same year as the appearance of Leonardo's Last Supper, a play about a family of undertakers tasked with preparing the funeral of Leonard da Vinci, only for the restless genius to stir from his coffin. It was through this follow-up piece to The Ruling Class that Durnin first discovered Barnes' work.

“Leonardo's Last Supper was the second professional piece of work I directed,” he says. “What struck me about it was the extraordinary imaginative leaps it made, and the extreme ways he used language. These traits were characteristic of all of Barnes' writing, and his theatrical voice was so different from other voices that were coming from his generation of writers at around the same time. I always vowed I would try and get back to his work, and I suppose now seemed like the ideal opportunity to dust down The Ruling Class and let it breathe again.”

Allowing the play to breathe is arguably something Medak's film version never quite enabled.

“I think the film tried to do too little to what is an intensely theatrical piece,” says Durnin. “It doesn't take enough risks in terms of opening out what's already there, so you lose some of the play's sense of daring. Although O'Toole's performance was rightly praised, the rest of it never quite leapt off the screen.”

As Durnin observes, The Ruling Class may have arrived in the seismic year of 1968, but Barnes' work never quite fitted in with contemporary barricade jumpers such as David Edgar, Howard Brenton and David Hare. While those writers went on to blaze various trails throughout the 1970s and beyond, Barnes maintained a more singular voice. This saw him write a series of largely historical works, including Noonday Demons, which appeared the same year as Leonardo's Last Supper, The Bewitched for the Royal Shakespeare Company in 1974, and Laughter! for the Royal Court in 1978. In 1985, Anthony Sher appeared in the RSC's production of Red Noses, which won an Olivier award. Despite such high profile works, Barnes remains a marginal figure whose plays were perhaps too clever to be embraced by mainstream culture.

“Barnes' writing never found any degree of fashionability in the way his contemporaries did,” says Durnin, “and even though he'd been writer in residence with the RSC, much of the latter part of his career he spent writing mainly for American TV. For someone so imaginative, that's really surprising, but it was difficult for producers to see that, even though he always stood out as being distinctive and separate from his contemporaries.”

Much of Barnes' singularity might be put down in part to his resistance to being pigeon-holed politically.

“Barnes was often guarded about taking any political stance,” says Durnin, “but while he would never be pinned down to any particular ideology, he always supported the underclass in his plays, even when he was writing about the upper class.”

Much of Barnes' side-lining might also be down to the fact that he wrote dark and complex comedies.

“Barnes had a great belief in laughter as a great leveller,” says Durnin. “His great hero was William Shakespeare's contemporary, Ben Johnson, who was similarly fascinated with looking at class, and who did that through humour and by using non-naturalistic language. Barnes could see how drawing on Johnsonian ideas of non naturalism could work. For him, laughter was a great unifier, and maybe that's why he didn't get the same respect that the likes of Edgar and Brenton received.”

Barnes' debt to Johnson can be found in his adaptations of The Alchemist, produced by the Old Vic in 1970, The Devil is An Ass, seen in Edinburgh in 1976 before transferring to the National Theatre a year later, and Bartholomew Fair in 1978. Barnes wrote My Ben Johnson in 1973 for radio, and it was through this medium he seemed to find another lease of life through several series of monologues, duologues and trialogues that began in 1981 with the much acclaimed Barnes' People.

Barnes's final stage play, Jubilee, was produced by the RSC in 2001, three years before his death aged seventy-three. The Ruling Class was last revived in a 2015 London production starring James McAvoy as Jack. With Durnin's take on the play about to open, both productions suggest that Barnes' unique dramatic largesse and sense of irreverence might finally have found its time.

“I think the play matters now because we seem to be living in an ever more divided world, where the things we used to take for granted are under more and more stress,” says Durnin. “While all of Barnes' work is about what divides us, he never had any pat answers, but never flinched from saying where the divisions come from.

“The Ruling Class is a piece that makes very clear how division and entitlement can exist alongside exploitation, and can drive people off the rails, but among all its darkness, it is also a relentlessly funny piece of work. Barnes forces you to recognise that the world he's depicting is inherently unjust and unfair, but by laughing at it, you can expose that unfairness more.”

The Ruling Class is at Pitlochry Festival Theatre from July 25, where it runs in repertory until October 14.

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