Stephanie Beacham played the tough schemer in Dynasty, but off stage it was close friend Marlon Brando who protected her from the Hollywood snakepit. She tells David Wigg why other men have failed to match up.

Stephanie Beacham first appeared on our TV screens as the tough but glamorous Sable Colby in Dynasty 15 years ago. Brought in as a rival to Joan Collins' wicked Alexis, the role turned Stephanie into a TV diva. Since then, she has become the top dog Phyl Oswyn in ITV's award-winning prison drama series Bad Girls, in which her character is serving five years for fraud. This month she plays another manipulative hostess extraordinaire in the play Dinner, a black comedy which also stars Gaby Roslin and Louise Jameson. 'I do feel that I have another venomous creature in me,' she says. 'This one I'm playing is desiccated and rude, but after a while you realise she's actually very sad. I have no fear of these awful women, because I consider myself to be a rather nice woman.'

Before Dynasty and The Colbys made Stephanie famous on both sides of the Atlantic, she had already been making a name for herself in Hollywood in the 1970s and starred in a number of films, including Michael Winner's The Nightcomers with Marlon Brando. Brando, who died just two weeks ago, was to become a lifelong friend.

Stephanie was 22 and had just left RADA when she got the part and was overawed at the idea of meeting such a major Hollywood star. 'I was so scared that he wouldn't like me and would have me fired, I said I'd only do the film if I could meet him first. Then, if he wanted to get rid of me, he could do so before we started filming.' A date with Brando was arranged at a private screening of a John Ford movie at Winner's home. John Trevelyan, the film censor, was a guest.

'Before the dinner I'd thought to myself,' she says, 'that Marlon has seen every beauty in the Western world, there's no point putting make-up on to impress this man. So I went without. The men were talking and I was just going to get a word in when John cut across my conversation. I was so embarrassed. But then I felt this great, thick, fat hand reach out and take mine and that was Marlon. He could see I was totally embarrassed. From that moment on he was completely and utterly protective. If I got cocky, he would play all manner of jokes on me. But if I was nervous, his hand was always there. If Marlon knew you were in discomfort he'd be wonderful, he had such sensitivity. We stayed friends, but he was a friend who was like a wild bear in the forest.'

One thing that struck her about Brando was his complete disrespect for good looks. 'He always thought his looks were a superficial asset. He was devastatingly handsome - the most beautiful man ever. But it was the power of the person that was most impressive.'

Stephanie was not shocked to hear of Brando's death, nor did she feel sad. She says, 'He was no longer a happy man. He was ready to reincarnate. He had not been happy since that tragic incident with his son, Christian, in 1990, and the death of his daughter, Cheyenne. That broke his heart and he was ready to die then. I don't feel sad, because he was ready to go - it was time for him to leave his body and soar like an eagle.' In 1990 Christian shot dead his half-sister Cheyenne's boyfriend, Dag Drollet, and was imprisoned for half of his ten-year sentence. Cheyenne, who had a history of depression and drug abuse, committed suicide five years later.

Although Brando was considered the best Hollywood actor of his generation, through charismatic performances, she says he never cherished his acting talent. 'Fortunately, other people did and producers and directors got him to work. But he once told me, as we went through a list of his films, that he was purely interested in what he could use the money for - "alimony, the Indians' cause, alimony, alimony, the Indians".' She explains that it was because he didn't care about his career that he never looked after his body and put on so much weight. Only a few years ago he told Stephanie that he was trying to lose weight. His reason? 'I'm too fat to be a lover'.

Stephanie admits that her first reaction on hearing of 80-year-old Brando's death from lung failure was one of guilt. 'I knew he had been unwell, but now I realise why he had not phoned lately. And I feel very guilty that I had not been in constant touch. Old people need us to be there for them. In future, I'm going to remember that.'

And what will she especially miss about Brando? Without hesitation, she replies, 'The man, his wonderful oddball humour and his compassion. He really was unique, a one-off.'

Although Stephanie had great respect for Brando, she has, in general, scathing opinions of most men. This has probably something to do with the collapse of her marriage to the actor John McEnery in the early 1980s, when she was left to bring up her two young daughters, Phoebe and Chloe, on her own.

'I thought, these two beautiful girls don't need the man around in the same way as they do a mother. They need to know who their dad is, and I always made sure there was total accessibility, but I thought, "I can cope with work and children. I cannot cope with the dynamic of the man, the husband. I'll do it myself.''' And she certainly did. Dentists, holidays, boarding schools - Stephanie paid for them all herself. 'I'm proud of that and proud, too, of how the girls have turned out. John said to me when we married, "Divorce is not a word in my vocabulary." I wish he'd used the word "infidelity" instead. We were married for 13 years, but it may as well have been three. This is a terrible admission, but I have never gone past what I call the "biological aperitif' of four years in a relationship. The drive for me to be with anybody has ceased after four years of being together. I find men so dogged. Inflexible. What they call logic, I call tiresome. Women can talk about God and shoes in the very same conversation.'

She admits she's impossible to live with and has become disillusioned with men. 'I've given up thinking that I would want to live with anyone.' She's not in a relationship now, but there's nothing she wouldn't contemplate. 'Isn't that the most fabulous thing about life? Keep your mind open and the universe will just come in and give you presents the entire time.'

After her unhappy marriage, she decided she would never marry again. But, after having seen how happy Joan Collins is with her fifth husband, Percy Gibson, Stephanie says she has had a change of heart and not ruled it out altogether. 'My soulmate could come into my life at any moment. I'm still romantic. But if I was going to be closely attached to a man, there would have to be a great deal of sex.'

Stephanie's manner is strong and positive, but some people have found her frosty, something she partly puts down to being hard of hearing - she is completely deaf in one ear and has only about 40 per cent hearing in the other, so she can be easily distracted. 'People have often said I'm a standoffish cow,' she says, openly. 'But you can't give your energy to everybody unless you're just a people-pleaser, and people-pleasers usually get let down.'

Recently, she had plenty to be pleased about when she bumped into Joan Collins at The Ivy restaurant in London. They talked about the new U.S. documentary that's being made about Dynasty, and started to compare how each looked, all those years later. 'Joan was the one who had the kindness to say - and definitely it's true of her - "Well, they could still use us. We haven't withered away.'" But the two women are very different. 'My idea of heaven is walking a dog along the beach. Joan's idea of hell is walking a dog along the beach. We don't see a lot of each other.' Does she miss the pampered Dynasty days? 'Do I miss wearing hugely uncomfortable shoes and too much make-up with hair lacquered to stiffness every single day? No. But I do miss all that glorious money.'

She used the money she earned from working in the U.S. wisely and bought a beach house in Malibu and another home in London. She passed on financial advice to friends, and shrewdly persuaded one of them to buy a house in the South of France. I met her nearby, at the Cannes Film Festival. She proudly produced a photograph of her four-year-old grandson, Jude, who diplomatically calls her 'Glamma' instead of grandma. She loves being a mother to Phoebe, now 29, and Chloe, 27, but Jude, 'is without doubt, the most important man in my life'. But she is not obsessed with glamour and hasn't had cosmetic surgery.

The truth is, I might be tempted if I thought I could get away with it - if it made people think I looked as fabulous as Catherine Deneuve. But I think I would rather grow old disgracefully in a wrinkled way. Look at my hands. They're 57 years old. Look at my poor little elephant's knees. Unless I could go into some machine and get my whole body done. what's the point? My wisdom, brain, wit and being are in my 50s. Why on earth would I want a face that didn't match my body? A brilliant acid-washed facelift would mean I couldn't go in the sun or garden any more. And I could name a number of people who have been profoundly unsuccessful at it.'

Stephanie, who was one of four children, grew up in north London. Her father was managing director of the Grosvenor estate, which owns large chunks of Westminster, and her mother was an exceptionally glamorous woman. There were times, during her teens, when Stephanie envied her mother's beauty and was made to feel insecure about her own looks. Her mother was so immaculately groomed that Stephanie cannot remember ever seeing her with her hair down. 'I think I learnt style,' she says, 'at my mother's knee.'

Her mother died of cancer in 1998 and her father followed three years later having suffered from Alzheimer's. To help her cope with her grief, she turned to spiritualists and psychic mediums. 'At first, Mummy didn't make a personal appearance, as I had expected her to,' but she says eventually her mother came through to her on more than one occasion. 'Mummy said she feels more love for us now, more than ever. This is a great strength. Maybe this is why I don't need a partner, because I have this.'

She does have two gay male friends in Texas. 'We're on the phone daily. They are caring listeners and they always have time for me. And they are often in tune with the way I am thinking. Things need to be expressed, but they don't necessarily need to be solved. No, I'll do that myself in the end.'

Dinner plays Richmond Theatre tonight; New Theatre, Cardiff, Tuesday to Saturday; Theatre Royal, Brighton, July 26-31; Oxford Playhouse. August 2-7.