City of Endeavour: Shaun Evans on Oxford, Morse and starring in the new series of Endeavour

I spot Shaun Evans taking a break from filming ITV series Endeavour, resting against the railings by the Radcliffe Camera, enjoying the warm weather.

A passing American tourist, immediately recognises him – Endeavour now being a worldwide phenomenon – and can’t believe her luck. Here is a bona fide star, on location, just minding his own business... and she immediately monopolises him.

Later, Shaun, well known for guarding his privacy zealously, laughs at my surprise and says: “I’m always available for people to talk to. Without our fans we would have nothing and Oxford is so accommodating to us.”

He says he knows the trouble Endeavour sometimes causes, taking up the streets with film crews: “So, of course, I stop and say hello now and again.”

It means that Shaun now has an intimate relationship with our fair city, not just because he spearheads Oxford’s very own iconic detective series, seizing the baton ably passed on from Morse, through Lewis to Endeavour, but because he spends so much time here, accessing parts most of its residents don’t even see.

“Yes, it’s a very special and amazing place for me. I didn’t know it well until Endeavour came along. But I love the colleges and The Bodleian, the Radcliffe Camera, the gardens and the quads, the beautiful little houses, so it’s an amazing job in that respect.”

So how did Endeavour come about for Shaun, a relative unknown until then? “My agent just called me and said: ‘this script has just come in’.

“I had just committed to doing something else for six months, but they said they were really keen, so I went out and bought Colin Dexter’s books.

“Once I started reading them I was really excited to see how this person became Morse and knew that it would be an interesting journey. And Endeavour really has been one of the most amazing experiences of my life.

A big responsibility though?“I just had to remember that there must have been a reason they chose me, something they saw in me and I had to trust them on that,” he replies.

Has Endeavour’s success taken him aback then? “We know the reaction is had already, going in, so it couldn’t be that much of a surprise, but it’s always interesting,” he said enigmatically.

He also bitterly refuted claims that, as this is now his fourth series, he can play the part with his eyes closed, as suggested in previous interviews.“It’s as challenging now as its always been, so no I can never rest on my laurels because it’s a big responsibility.

Dodging questions about owning his own character, he would only say: “We all want the same goal, so it’s never really a case of ‘my character wouldn’t say that’

As for any plot divulging, Shaun remains tight lipped :”You’ll just have to wait and see,” he teases, “ I can’t say too much

So does he worry about Endeavour’s inability to form serious female relationships? “I never really think about that. I just get on with it and hope people enjoy it.”

Enigmatic until the bitter end. What we do know about this fascinatingly aloof man, both on stage and off is that Evans’ family is from Northern Ireland. He was born and raised in Liverpool, Merseyside, where his father worked as a taxi driver and his mother was employed as a hospital health care worker. He gained a scholarship to St. Edward’s College, completed a course with the National Youth Theatre before moving to London, where he still lives, at the age of 17-18 to study at the Guildhall School of Music and Drama.

His first major role was that of gay French teacher John Paul Keating in the Channel 4 comedy-drama Teachers. The following year he made his feature film debut in The Boys from County Clare, starring alongside Bernard Hill, Colm Meaney and Andrea Corr, with whom he then went out with.

In 2012, Evans played the role of new pupil Daniel in BBC legal drama Silk alongside Maxine Peake and starred in the ITV series The Last Weekend.

Then came Endeavour and changed everything that came before, which has since been recommissioned for four new seasons by ITV.

So how much has Endeavour impacted things? “It hasn’t really changed my life. I’m very lucky really. Of course the job does afford me the luxury of being a bit more picky, and of course as an actor so I’m grateful for that

“But it’s a team effort and I work with such an incredible group of actors as well as some amazing guest actors, and it’s their commitment that makes Endeavour such a success,” he says unhelpfully.

Does he mean Roger Allam, with whom Shaun must spend an inordinate amount of time: “Roger is an absolute legend and I have a massive amount of respect for him. We are great pals now of course. And hang out quite a lot.”

As for the future, what of another series? “An actors work is never guaranteed so we reassess at the end of each series, year by year. Nothing is taken for granted, but that’s not my incentive anyway.

“I just work hard to get these amazing stories told while the demand is there and I really enjoy it. It’s something to strive for.”

Shaun Evans takes the title role in Endeavour in the new series – set in Oxford – which starts on Sunday on ITV