Antony Sher is returning to some of his greatest roles – at one remove. He talks to Terry Grimley about playing one of the 19th century's most notorious actors.

Among his many other roles, Antony Sher has made a particular impact in the roles of Richard III and Shylock: now he's playing another actor who did the same.

In a rare revival of Jean-Paul Sartre's 1954 play Kean he is playing the early 19th century Shakespearean actor Edmund Kean, who electrified his contemporaries – Coleridge said that to see him performing Shakespeare was like seeing it illuminated by flashes of lightning – but burned himself out at the age of 56.

The production, directed by former RSC artistic director Adrian Noble, is at the Malvern Festival Theatre this week as part of a pre-West End tour.

When I spoke to Sher last week he was at the Theatre Royal, Bath, a theatre where Kean himself appeared between his big seasons at Drury Lane. He is the first actor to have played the part since Derek Jacobi in 1990.

"It hasn't been done much. Prior to Derek doing it there was a production with Alan Baddeley in the 1970s which I think was the first time it was done in this country.

"Then there was a TV version in the 70s with Anthony Hopkins. I saw it each time and was very fascinated by it, and it's something I've been talking about doing for quite a few years."

What's it like playing an actor famed for roles he has played himself?

"It's a real hall of mirrors, but that's what I love about the play. Originally it was written by Alexander Dumas and then Sartre did this version in the 1950s. He did precisely that, putting the hall of mirrors into the play – what is acting, what isn't, breaking through the fourth wall in the theatre. You have this moment when Kean breaks through and speaks directly to the audience.

"Added to that, there's the fact that I'm playing an actor playing various parts that I've played myself."

In an era before rock'n'roll it seems to have fallen to classical actors to give audiences the vicarious thrill of walking the tightrope of excess. Kean did eventually crash and burn on stage, suddenly collapsing during a performance of Othello and saying to his son Charles, who was playing Iago: "O God, I am dying. Speak to them, Charles." He actually died two months later.

"The character of Kean is quite dangerous," says Sher. "He's a really wild character – in modern terms it would be Oliver Reed or Richard Burton. He's an alcoholic, a womaniser, on a course of self-destruction.

"He's on a knife edge all the time, destroying his genius. I would give anything to be able to go back in time to see him perform."

But there is a problem, because despite tantalising eyewitness accounts like Coleridge's it is impossible to be sure what Kean's acting was like. The suspicion, of course, is that it would seem inflated and melodramatic by modern standards.

"Adrian Noble and myself decided in the end that you can't reproduce the acting style of another time. You would probably end up sending it up, making it look ludicrous. Even when you see that grainy, dark footage of actors at the beginning of the last century, it seems extremely dated.

"We thought why don't we, when we see him doing the bits of Shakespeare, just do it as well as we can? So when I perform the bits of Richard III, Othello and Shylock, I just do it as well as I can."

If nothing remains of Kean's performances, what makes him worth remembering today?

"Historically he's important because he's in that great line, Burbage-Garrick-Kean-Irving-Gielgud-Olivier, that line of the great actors. But what he did was break the mould of what a classical actor could be all about. He was short, dark, demonic.

"He had quite a rough childhood, and went into acting by being apprenticed to a small company of travelling players who played fairgrounds. But the play isn't a biopic – it simply takes some of the historic facts and then takes flight from that.

"I think it's a terrific piece and audiences have been responding to it with great enthusiasm."

* Kean is at the Malvern Festival Theatre until Saturday (Box office: 01684 892277).