The big man was standing in a marquee near his swimming pool, a white towelling bath robe loosely knotted round what passed for his waist, joking with guests invited to his 44th birthday party on the lawns of his Oxfordshire mansion, as the pretty blonde 16-year-old was introduced to him by her brother.

When her host, complimenting her on her bracelet touched her wrist, she felt breathless. Youthfully inexperienced, she did not at first realise why. Then, as she recalls today:'It suddenly dawned on me that he exuded an extraordinary, brutal power.'

The two were Eleanor Berry, fourth child and second daughter of the late Pamela and Michael Berry (proprietor of two national newspapers) and Robert Maxwell, flamboyant publisher and later owner of the Daily Mirror. And by any account theirs was to become the most extraordinary relationship.

When, despite the hundreds of guests circling the grounds of Headington Hill Hall that June day in 1966, Maxwell put down his glass of champagne, stubbed out his half-finished cigar and took her in his arms to dance, he aroused in Eleanor a craving for his attention that was to be her obsession for years.

And when he told her to find a bathing suit, picked her up on her return in a skintight costume, carried her to the pool, threw her in and watched her swim around, she knew she was in love. The next time she saw him, again at Headington Hill Hall, she was so overcome by her feelings that she fainted. When he read to her in Russian after she had been put to bed to recover from her dizziness, she was overwhelmed - and determined to learn the language secretly so as to surprise him (she did, in six months).

Today, Eleanor Berry is a handsome blonde with a steady, deep voice (Basso Profundo was one of Maxwell's nicknames for her), an Honours degree in English from Sussex University, a part-time job as an assistant to a Harley Street doctor, a passion for the cinema, and the air of one who has been through trauma and emerged on the other side.

You see, in her teens she says - and she and her father are quite open about this - she suffered from schizophrenia and, later, Valium addiction, neither of which, both say, she suffers from today. When she met Maxwell she was in her last term at Wycombe Abbey and about to start studying for her A-levels in Oxford.

'We all knew about Eleanor and Bob Maxwell. She had a schoolgirl crush on him, though he was never her boyfriend,' said her father yesterday. For Eleanor, it was not so much a crush as a passionate obsession. The man born Abraham Hoch in a tiny Czechoslovakian village was 'a hulk of a man, who looked like a beautiful black labrador', as she puts it in her just published memoir, Robert Maxwell As I Knew Him.

For the next 15-odd years, her life revolved round visits to Headington. 'It was quite near our house,' saysher father, 'and she would often go and stay there. She became a great friend of the family and even helped Betty Maxwell send out their Christmas cards.'

For Eleanor these visits were a focal point. 'I used to be incredibly excited before I went to stay there. I spent hours deciding what I was going to wear. He liked yellow so I often wore that. I bought a yellow leather suit, which he liked, then in the summer I would wear yellow trousers and a white t-shirt. And there was a pair of red snakeskin boots of mine he loved - excrutiatingly uncomfortable, but I always wore them.'

She dyed her hair black because it was the colour of his ('I wanted to be as close to him as possible') only desisting when, after two years, he told her it didn't suit her. Soon she was staying at Headington. 'I felt it was a wonderful chance to be near my idol.'

Quickly, she learned the main house had rules: early rising and the equivalent of a conversational green baize door.'If you had lunch in the kitchen you were allowed to be quite ribald, but if you were having lunch in the dining room, your conversation had to be pretty clean. Betty didn't like ribaldry even in the kitchen but he didn't seem to mind.'

His own eating habits were bizarre. 'He used to reach across the table, grab whatever he wanted and shove it into his mouth. If he was eating a chicken he would pick it up whole and eat it as if it were a bar of chocolate and throw the legs into a corner - he'd only use a knife and fork at the dining table.' He was a foodaholic, she says. 'He used to break into the larder in the middle of the night. People had to keep watch to see he didn't. When I was first there they padlocked it but he just broke the door down. I didn't find it off-putting, I just thought it very amusing.'

After a while her mother became alarmed at the amount of time Eleanor was spending with the Maxwells and sent the family chauffeur to fetch her. Extraordinarily, her mother was not anxious about her 17-year-old daughter on moral grounds, only on social ones. 'My parents weren't worried. My mother thought I'd outstayed my welcome, nothing else.' Three months later Eleanor invited herself to stay again and from then on spent as much time at Headington as she could.

She felt like a part of the family, she says. She was also devoted to Maxwell's French-born wife Betty, who would talk to her of Flaubert and Balzac, Proust and Mallarme, as they peeled potatoes together. She helped her idol canvas for the Labour Party when he stood as candidate for North Bucks - and when he gave her a rare ticking off was so disturbed, she got drunk. A certain awe in fact, was an integral part of the compulsion that drew her. 'I was mesmerised by the way he could control everyone around him. He realised that the only way to get anywhere was to terrify people, and he taught me to do so. When I did do so, he said "Not in my bloody constituency!".'

He liked her, she says, because he thought she was wayward, sharp-tongued and outspoken. 'Maxwell liked bold, forthright, pretty, rather noisy women. For some reason he also admired me because I'd joined the Communist party and taught myself Russian.'

Today, she says that what she wanted was his attention. If she lost it, a black cloud would engulf her; sometimes she would speak to him in Russian, so that other people in the room were left out. In June 1988, Maxwell had a 65th birthay party. Eleanor went wearing white leather trousers, a white V-necked sweater, and those red snakeskin boots, now almost worn out but still just as painful.It was the last time she saw him.

'When I heard that he was missing at sea, I became hysterical. I simply couldn't believe it.'

After his death she persuaded Betty to give her two of his shirts,which she still wears as nightshirts. She has kept all his letters, brief, affectionate typed notes signed 'Yours ever', and she is in touch with the family. 'Ian is the one I like the best - he's got such a sweet personality and he looks like his father. He took a lot of flak from his father.' One child, and she is not saying which, has been traumatised by their extraordinary upbringing; the other six are all right. 'Ghislaine is the strongest of all. She's very like her father.'

He was very intolerant of other men, she adds, perhaps because he had been absolutely terrified of his own father, and he frightened men more than he frightened women. 'I don't think Betty was frightened of him but he used to bark at her quite a lot, particularly in his later years.'