Sian Phillips: From a remote farmhouse to headline billing – everything that Sian imagined

But if you were looking for a female equivalent then Sian Phillips would surely be it. In an acting career spanning more than half a century she has appeared in films alongside Richard Burton, John Hurt and Daniel Day-Lewis, and has worked with some of cinema's most revered directors, such as David Lynch in Dune (1984) and Martin Scorsese in The Age of Innocence (1993). Her notable television performances include Katerina Ivanovna in Crime and Punishment and Livia opposite Derek Jacobi in I, Claudius, for which she won a Bafta for best actress, while her West End credits include Pal Joey, Gigi and Calendar Girls.

As well as being one of Britain's best known actresses, her performance as Marlene Dietrich led to an international cabaret career and she has also written her own stage show, Sian Phillips – Crossing Borders. Throw in a celebrity marriage to Peter O'Toole and a CBE for her services to the performing arts and you have the outline of a remarkable theatrical life, albeit one that grew from the most unlikely of surroundings.

Sian was brought up in a remote farmhouse in south west Wales, where her family had been hill farmers for generations. But it was the stage, rather than the field, where her future lay.

"I wanted to be an actress when I was six, before I'd even seen a play, although I have no idea why. There weren't any theatres where I lived in and it took a long time to travel to Swansea," she says. "I had a wonderful great-aunt who was an evangelical preacher and I was brought up with this oral tradition where people talked a lot. You would go to chapel and the preachers were like performers, because they had to be. Sometimes they would give a sermon for an hour-and-a-half so they had to be gripping."

Despite her enthusiasm for acting, her family were against the idea. "They didn't want me to go into the theatre because they thought it would be too hard and that I wasn't tough enough. But I never changed my mind and it was exactly as I imagined it would be." Which was? "Nice," she says.

Sian is speaking prior to her visit to York University, last night, where she was the special guest at the launch of a new book, Playing for Real: Actors on Playing Real People, written by two of the university's lecturers, which features interviews with the likes of Sir Ian McKellen, Jeremy Irons and Sian herself. She admits that playing the iconic Hollywood diva Marlene Dietrich, in Pam Gems's one-woman show Marlene, was arguably the most difficult role she's ever had. "When I started it was a bit of a nightmare because of who she was. At one time she was the highest-paid actress in the world, she was the most beautiful woman in the world and most famous cabaret singer in the world, so playing a real person, and particularly someone as famous as Marlene Dietrich was daunting.

"But the most important thing for me was getting the songs right and I did three months training and had to lower my voice so I could sing in her key." The show was a huge success, with Madonna and Shirley Bassey among its showbiz fans, paving the way for her own cabaret career.

Despite the earlier objections of her parents Sian's determination to become an actor never wavered and she gained a place at Rada while still a teenager, by which time she was already a seasoned performer. "I'd been acting since I was 11, I worked with the Welsh National Theatre Company and I'd been a BBC programme announcer on Children's Hour, so I was used to working and being on stage."

She arrived at Rada just after Albert Finney, Tom Courtenay and Peter O'Toole, who she calls "that group of brilliant young men", had left. In 1959, she married O'Toole, before Lawrence of Arabia transformed him into a Hollywood star. Their marriage lasted 20 years and the couple appeared in several films including Becket (1964) and Murphy's War (1971). "We did work together but not as often as people may think and we tended only to do so when we had to," she says.

For Sian, film always came second to performing on stage. "The theatre was what excited me the most, it was where I felt at home." Even so, she is still probably best known for her portrayal of Livia in I, Claudius, the BBC's acclaimed adaptation of Robert Graves's epic novels about the decline of the Roman empire. As well as redefining the boundaries of TV drama in the 70s, it also gave her the chance to work with the likes of Derek Jacobi, John Hurt and Brian Blessed.

"We had no idea it would become so popular because it was one of a number of dramas we did at the time. It exceeded everyone's expectations and it was great fun to work on, it was a bit like being part of a rep company again."

As a veteran of the stage, Sian has seen the business change over the years, but has it changed for the better?

"It has changed, undoubtedly, there's no repertory theatre any more and I think that's made it harder for actors because they don't have the same opportunities to practice," she says. "It used to take people 10 years to make a name for themselves, even the movie stars. You didn't have overnight success, whereas nowadays someone can become a household name after being in a soap opera for a couple of weeks."

This isn't sour grapes, merely an observation on how the world has changed since she started learning her craft. What does concern her, and indeed many of her peers, is the dearth of decent acting roles for women as they get older.

"This is a problem. Shakespeare wrote some great parts for men as they get older, like King Lear, Claudius and King Richard, but unfortunately there are very few for women. There's the nurse in Romeo and Juliet and Mistress Quickly in Henry IV, but they aren't on the same scale."

However, last year, at the sprightly age of 76, she was asked to play the title role in a radical retelling of Shakespeare's Romeo and Juliet at the Bristol Old Vic. In this adaptation all of the main characters were pensioners and the romance between the star-crossed lovers was blocked by their children rather than their parents.

For Sian, who never had the opportunity to play this iconic role during her youth, it was a real thrill. "It was wonderful, it was set in a care home and it went very well. But I just couldn't get over the fact I was actually playing Juliet," she says, laughing.

As for the future, there are radio shows and a play she might write, as well as her popular cabaret show featuring some of her favourite musical numbers and songs by everyone from Noel Coward and Jacques Brel, to Billy Joel and Joni Mitchell.

"It's quite eclectic", she concedes, although in many ways it reflects her own career. "I don't think it's necessarily very good to be versatile, because people much prefer you to be very good at one thing. But it depends what kind of career you want and I suppose mine has been a little different to most people's, but I feel I've been very lucky because I enjoy what I do."

It has, as she says, been everything she imagined.