Religious figures – the Pope and the Archbishop of Canterbury, to name but two – have been his stock in trade for years. For four seasons he was the 12th century TV monk Brother Cadfael.
“But I also played Hitler,” he points out.
His film credits include The Day of the Jackal, Henry V, Gladiator and The King’s Speech, none of whose scenes were shot next to a Vietnamese restaurant in Ilkley. Today’s production, a black comedy about a high church cleric who puts out a contract on a militant atheist at the local literature festival, is somewhat less ambitious.
Jacobi turns 80 next month and, in the course of some 60 films, has been directed by the greats: Kenneth Branagh, Robert Altman, Sir Ridley Scott. Today, his director is Harry Michell, a 26-year-old who has made only one feature before. It must be daunting for the lad, someone suggests.
“Oh, I sincerely hope I’m not daunting,” says Jacobi, with real concern. “I think one thing I’ve learned over the course of 58 years in the business is not to daunt.
“Always doubt. Never believe that you’ve made it, that you’ve got there, that you know it all.”
He flinches, he says, when people ask him to give masterclasses on acting. “I could no more give a masterclass than fly to the moon. Acting is such an individual thing. I couldn’t teach anyone how to act. I could describe perhaps with difficulty how I do it, but that’s not the same as teaching somebody to act.”
But there’s a technique, surely?
“There is a technique, yes. And what’s interesting about that is the difference between theatre and film, with television the halfway house.”
The theatre is his first love. It was where Laurence Olivier discovered him, and invited him on board as a founder member of what is now the Royal National Theatre; where he played Hamlet, Lear and Malvolio. But it was television that allowed the rest of the audience to find him.
More than 40 years after it was committed to video tape, his stammering, twitching Emperor Claudius in the BBC adaptation of Robert Graves’ novel is still his defining role. Its worldwide success prompted the wit Denis Norden to observe that it had led a generation of Americans to believe that Claudius was a Roman emperor whose first name was Ike.
Yet, Jacobi reveals, he was not the first choice for the role, nor even the second. Somewhat incredibly, the role could have gone to Ronnie Barker – an actor whose stammering, twitching Arkwright in Open All Hours was rooted more in Rotherham than Rome.
“It came absolutely out of left field,” Jacobi says. “Originally, they wanted Charlton Heston, and they were going to have two Claudii – a young one and an old one.
“Heston was the choice for the old one, and when they didn’t get him they thought of Ronnie Barker. But then the producer decided that they wanted the same actor to age with the part, so that you stayed with the same face.
“That was good for me and I got it. I was very lucky.”
Unconcerned at being forever associated with a single role, Jacobi says it is “wonderful” that people can still be found who remember it – love it, even. “They don’t make TV drama in that way any more. It was very theatrical. We were like a theatre company, and it was filmed in a theatrical way, with multiple cameras.”
The theatre, he says, is where his heart is. It has been so since the sixth form at Leyton College in Essex, where he first played Hamlet. The show was taken to the Edinburgh Fringe and he went on to a scholarship to Cambridge.
Ian McKellen and Trevor Nunn were there at the same time. McKellen confessed years later to having a crush on Jacobi, but said nothing at the time. Jacobi, meanwhile, took his Hamlet on the road, and while on a tour of Switzerland he met Richard Burton, whose film career was burgeoning.
He left Cambridge with a degree in history, but the greasepaint had stuck, and he went straight into rep in Birmingham, from where Olivier plucked him, and he was Laertes in the National Theatre’s inaugural 1963 production of Hamlet, with Peter O’Toole in the title role.
He was still winning plaudits as recently as two years ago, as Mercutio in Kenneth Branagh’s Romeo and Juliet at the Garrick in the West End.
Yet the security of film is hard to resist, he admits.
“I’ve always enjoyed the stress of theatre – standing in the wings thinking, ‘Why do I put myself through this night after night?’ But suddenly, I find I like the relatively stress-free atmosphere of filming, where you’re surrounded by safety nets.
“In theatre you’re not, you’re on your own, and that’s the joy, that’s the thrill of it. But I do like safety nowadays.”
His next screen role, on location in Oxford, will bring him full circle. He plays Robert Graves’ father in The Laureate, a transatlantic production about the novelist’s early life with the American poet Laura Riding during the First World War. Kathy Bates is among his co-stars.
The Ilkley shoot – it’s the name of the film as well as its location – is a more modest affair, which was partly why Jacobi was drawn to it. “It’s lovely when you get to my age to be able to work with the young and the thrusting and the upcoming,” he says of Michell.
“I play a rabid Protestant, who thinks he’s an evil mastermind. He’s a bully and, like most bullies, he’s a coward. Not a nice character – not very nice at all. But they’re often the most fun to play.”
The action takes place during the annual Ilkley Literature Festival, the non-fiction version of which begins on Friday. The organisers have licensed their name to the filmmakers, and the plot sees Jacobi’s Father Enoch travel to the town to deal with the brothers he has hired to assassinate the militant atheist, but who have picked off the wrong man.
If it sounds far-fetched, a glance at the festival’s history suggests otherwise. At the inaugural event in 1973, the poet WH Auden got into a fracas with a local vicar over which version of the Bible to use. And only last year, the evolutionist Richard Dawkins addressed a sold-out audience at the King’s Hall.
Jacobi laughs uproariously when told that Dawkins got out of town to tell the story. “They missed!” he guffaws.
His street scene on Railway Road is part of a chase that will, when the film is cut together, have begun on Ilkley Moor, by the Cow and Calf rocks. When, by lunchtime, the black car has driven away and the shot is in the can, his work on the production will be done. It has been, as these things go, a quick job.
“I hadn’t even been to Ilkley until yesterday,” he says. “We’d been filming inside the Cairn Hotel in Harrogate. I’ve been up a week. Just a week’s filming. Perfect time.”
■ Ilkley will be released next year. The Ilkley Literature Festival opens on Friday and continues until October 14.