Sir Ian McKellen is going back to his theatrical roots – in Coventry, he tells Roz Laws.

Sir Ian McKellen is wracking his brains, trying to remember how he felt when he stepped out on stage in his first professional role.

“Come on, it was 50 years ago!” he cries in a bid to excuse his memory lapse.

I venture that perhaps he felt nervous, as a fresh-faced 22-year-old in his first job at Coventry’s Belgrade Theatre.

“Oh no, I wasn’t nervous, I don’t think,” he muses. “I have never been nervous about an audience, I have always enjoyed acting so much.

“And I wasn’t aware at the time that it was such a big deal, that this was the first role of a career and where it all started. I hadn’t actually decided then to be an actor.”

In hindsight it was, however, a very big deal and one that Sir Ian – who is also in the West Midlands this week at Malvern Festival Theatre – is about to commemorate.

On Sunday, September 4 he is returning to the Belgrade to celebrate his career half century with a fund-raising event. He will chat about his life and craft and answer questions from the audience.

Sir Ian is especially pleased that it will be 50 years “to the minute!” since he played Roper in A Man For All Seasons.

After strutting his stuff on the Cambridge University stage with the likes of Derek Jacobi, Trevor Nunn and Margaret Drabble, he auditioned at several local repertory theatres.

He was offered jobs at Derby Playhouse and Hornchurch Theatre, but the Belgrade – then only three years old and the first civil theatre to be built after the war – offered him the highest salary, of £8 10 shillings a week.

Out of his wages, he paid £3 3 shillings to live in one of the theatre’s own flats.

“I had a wonderful time,” remembers Sir Ian, now 72. “I relished having such a wide range of roles, from Shakespeare and Agatha Christie to Chekhov, and working with some fantastic people like Leonard Rossiter.

“We used to drink after hours in the pub in the car park opposite.

“It was an exciting place to be. Coventry had taken such a battering in the war, but it was determined to get back on track. The new cathedral and precinct had just opened and there was a spirit in the air of ‘we are the future’.

“I haven’t been back at all since, so it will be nostalgic to return.”

But what of his very first role? His memory is still largely a blank about that.

“I asked our director, David Forder, about it. He remembers me wearing a pair of chef’s checked trousers on the first day of rehearsals, which he found alarming. So do I, I can’t recall having such an item in my wardrobe!

“He says I was bouncing up and down and was so enthusiastic. I don’t recall any of my lines in the play. It was enough for me that I had some lines, I was just thrilled about that.”

Sir Ian, of course, has gone on to have some truly iconic roles with plenty of memorable lines.

He was Gandalf in Lord of the Rings and Magneto in the X-Men films. He was Sir Leigh Teabing in The Da Vinci Code and Mel Hutchwright in Coronation Street. And on stage he’s been everyone from King Lear, Macbeth and Iago to Widow Twankey in panto. He even played himself in an episode of The Simpsons.

At the moment, Sir Ian is starring at Malvern Festival Theatre in The Syndicate, in what he describes as “a fantastic part, one of the best I’ve ever had”.

Running until Saturday, the play by Eduardo De Filippo sees Sir Ian play a Mafia Godfather in 1960s Naples. Antonio Barracano is a killer who rules the Naples underbelly with a rod of iron, providing a form of rough justice for the city’s criminals.

“I take on roles on the basis of ‘is it something I would like to see?’,” reveals Sir Ian. “And this part intrigued me. I was immediately attracted to it.

“I’ve known De Filippo’s other plays and have done one of them before – Napoli Milionari, 20 years ago at the National. The Syndicate has never been seen here before.

“Antonio wields a gun and is strict but not totally selfish, he’s trying to get people to behave and stop being violent. He’s trying to sort out injustice in a moral vacuum.

“I just play him, it’s up to the audience to make up their own minds about his ethics. Some people think he is absolutely hateful, but some of his judgements are really quite witty. He adores his family and his dogs and he can be quite humane.”

The setting, of a society which has broken down and where the police struggle to keep to order, sounds rather similar to recent events in riot-torn Britain.

“It is familiar, isn’t it?” says Sir Ian. “We certainly couldn’t have anticipated those parallels.

“Who knows, we might get vigilantes taking over, and then how long will it be before some sinister gentleman like Antonio comes round saying ‘the police can’t protect you, but I can’.

“Luckily our society has not broken down as badly as Naples. But how does a society stay in control, what’s to stop it just blowing apart? That was the worrying thing about the riots. Why did it happen and will it happen again?”

First staged at Chichester, The Syndicate also features Michael Pennington and Cherie Lunghi and is on a short regional tour until mid-September.

That’s when Sir Ian must hasten back to New Zealand – and Middle Earth – to reattach Gandalf’s long beard for the two films of The Hobbit.

“It was written into my contract that I must have time off for a play, as making two films takes a long time.

“The Hobbit is proving enjoyable, though. A lot of the people are the same as on Lord of the Rings – Peter Jackson, of course, and many of the technicians and artistic crew, and cast like Cate Blanchett, Elijah Wood, Orlando Bloom and Andy Serkis.

“But we also have a lot of new input, with people like Martin Freeman, James Nesbitt, Stephen Fry and Benedict Cumberbatch.”

As The Hobbit is a prequel to The Lord of the Rings, I wonder if, strictly speaking, Gandalf the Grey should look a little younger.

“Well he is over 6,000 years old, so I don’t have to look that different,” he smiles.

When The Hobbit finishes filming next year, Sir Ian hopes to take The Syndicate into the West End.

What he’s not planning on is appearing in any more X-Men films. It seems a touchy subject.

“They’ve done a couple without me and probably they have outgrown me,” he says. “It’s very unlikely I will do any more.”

Just before he goes, I ask Sir Ian if, during his trip down memory lane at the Belgrade, he is likely to shed a tear.

“It is an entirely sentimental idea of mine and I wouldn’t be surprised if I am quite emotional,” he confides.

“But I don’t think I will cry. If I did, it would only be from happiness. I’ve had a lovely career and it’s still carrying on.”

* For tickets for Back At The Belgrade, go to www.belgrade.co.uk

* For The Syndicate go to www.malvern-theatres.co.uk