IN the summer of 1968, David Edgar came to Edinburgh as a 20-year-old undergraduate to perform in a student production of The Mandrake, the only play by Italian renaissance philosopher and poet Niccolo Machiavelli, and here rewritten as a musical. Edgar played the Apothecary. Fifty-one years on, the veteran writer of epic state of the nation plays including Destiny and Maydays makes a belated return to the Edinburgh stage in his already successful solo piece, Trying it On.

In the play, the now 71-year-old Edgar is confronted by his younger and arguably more radical self, who arrived in Edinburgh fired up by the seismic events of 1968. The student uprisings in Paris, London and elsewhere, the Prague Spring, anti-Vietnam protests and the assassination of civil rights giant Martin Luther King had all left their mark. For a young man just starting out in the world, it was a lot to take in. It also proved to be an inspiration for everything that followed.

“There wasn’t a better time to be 20 in the second half of the 20th century than 1968,” says Edgar. “I was in second year at university, and we came to Edinburgh that summer with what, looking back, was an extraordinary company. Mike Alfreds had written it, and we had Ian Charleson, David Rintoul and Tim Piggott-Smith in the company, and we were all doing this literally as the news of the tanks rolling into Czechoslovakia that marked the end of the Prague Spring was coming through.

“All these things were in progress, and we felt close to history, so it’s a very personal story about my relationship with my younger self. It also asks why my generation, who lived through the turmoil of 1968 and everything that came after, voted for Brexit. Obviously that story is moving on, but I think that question is still pertinent.”

Edgar’s youthful self moved into journalism in Bradford, where he fell in with future Traverse Theatre director Chris Parr, then involved with the Bradford University Theatre Group. Early plays by Edgar were seen at the Traverse and Edinburgh’s now lost Pool lunchtime theatre. These were either politically driven, such as Bloody Rosa, which told the life story of Rosa Luxemburg, or voguishly poppy in the way of Acid, which featured a Charles Manson style massacre at a pop festival on the Isle of Wight.

Edgar co-founded radical troupe, The General Will, which presented cartoon style political critique interspersed with music hall and burlesque. Next came England’s Ireland, a collective response to Bloody Sunday, when British soldiers shot 28 unarmed civilians in Derry during a protest march against internment. Edgar and fellow writers Tony Bicat, Brian Clark, Howard Brenton, Francis Fuchs and Snoo Wilson holed themselves up in an isolated cottage to write the show, which played at the Mickery in Amsterdam and the Roundhouse in London.

“That was the first thing I did after I left journalism,” says Edgar. “We wanted to write about the contemporary world, but the danger of that is the work dates.”

Edgar’s work was seen at various small theatres, and in 1976 his play, Destiny, was picked up by the Royal Shakespeare Company. Destiny looked at the rise of the far right, and arrived at a time when the National Front appeared to be making gains among the traditionally Labour voting working class. More than 40 years on, the play sounds dangerously current once more. As Edgar points out, however, the warning signs had been there all along.

“Both Ronald Reagan and Margaret Thatcher had been on the left in their youth,” Edgar points out, “then defected. What happened after that anticipates what we’ve got today. When Democrats like Reagan became Republicans, they went on to become the bedrock of Trumpism. It was the same when Thatcher sold off council houses, and managed to do better among working class voters than Labour, so the late 70s and 80s were a dry run for what’s happening now.”

When Trying it On was first seen at Warwick Arts Centre last year in a co-production with China Plate, who revive it for its Edinburgh run, it coincided neatly with a new RSC production of Edgar’s 1983 play, Maydays. That play charts the rise and perceived fall of post- 1968 idealism through the journey of a protagonist who begins the play as CND badge wearing public schoolboy who goes on to become a political activist. By the end of the play he’s working for a right wing think-tank and sneering at his former comrades at Greenham Common.

Edgar’s updated version accommodated the fall of the Berlin Wall, Iraq, Brexit, Trump and Grenfell. It even offers its former revolutionary hero two choices in which way to go. In this respect, Maydays and Trying it On are two sides of the same coin.

“In a way Trying it On tells the story behind Maydays,” says Edgar. “With Maydays, we had actors under 40 asking what the Cuba missile crisis was, and I had to make what was a contemporary play into a history play. While the main character in the play was inspired by revolutionary politics the same way I was, the difference is that in his thirties he moved to the right, while I didn’t.”

Whether this will satisfy Edgar’s younger self in Trying it On remains to be seen. With the rise of Occupy, #MeToo and now Extinction Rebellion, there is also a new generation of activists to think about.

“The relationship between me now and me then is the relationship between the movements then and the movements now,” says Edgar. “It’s easy for someone from my generation to think of all the things that were achieved politically, and that no-one else is allowed to be angry. So when a new generation emerges and says how dare you think you’ve achieved things and say we have no right to be angry, I think you have to listen. Some of the things that are happening now are very evocative of the late 1960s, so when a younger generation comes to sees the show, they can see that the movements they’re involved with have been around before, and that that’s okay.”

Trying it On, Edinburgh Festival Fringe @ Traverse Theatre, Edinburgh. Previews July 28 and August 3, then August 4-25, various times.