His friends called him Terry.

I can't say for certain this fact is important but I'm thinking it might be. The other two members of what the portrait and fashion photographer Norman Parkinson dubbed the "black trinity" – those photographers who reframed the 1960s, made it look clean and shiny and new – were known by their surnames. Bailey. Duffy. There's a kind of built-in distance to those names. Maybe that said something of their personalities. But Donovan, Terence Donovan if you wanted to be formal, was always Terry to his mates. To them he still is.

"Terry was an amazingly caring person," David Hillman, who first met Donovan when they both worked on London fashion magazines in the 1960s, says. "He'd always ask, 'Are you all right? Can you afford to pay the milk bill?' He was always worried about your wellbeing." David Puttnam, now Lord Puttnam, says the same. He tells me his Stardust story. In 1974 he'd made a movie starring David Essex called Stardust. It set a new UK box-office record. There was a poster up on Wardour Street in London saying as much as Puttnam came out of a meeting with his bank manager, who'd just told him he was broke. It was Donovan who pulled up in his Rolls-Royce 15 minutes later with £300 in cash to get him through the month. "He said, 'There's one condition attached to this,'" Puttnam recalls. "'It is never mentioned again. Ever.'"

That's the man they remember. Donovan. Terry. The self-made millionaire, an east London boy made good, a Buddhist, a judo black belt, a man who didn't suffer fools gladly, a man full of life until his unexpected, inexplicable death at his own hand in 1996. Both men knew the photographer too. It's the photographer who is remembered in a new book, co-edited by Hillman and Donovan's widow Diana. Terence Donovan Fashion, a book that traces his eye from the sixties to the nineties, from Twiggy to Naomi Campbell and beyond.

It's a book that opens with the shock of the new and then progresses through seventies flounce and eighties power-dressing. It is a book that is the story of fashion photography in the UK over the past 60 years. And Donovan was at the heart of that story. Along with David Bailey and Brian Duffy he started it. "They legitimised photography," suggests Puttnam. "They made it sexy. Prior to those guys photography was a pretty arcane thing. What Bailey, Duffy and Donovan did was take it to the mainstream and made it part of all our lives."

Donovan, Norman Parkinson once said, might have been the most talented of the three. He was technically expert, knew everything there was to know about cameras and his 1960s images have a crispness to them, a sharpness, a freshness that was new.

I guess if you think about it we've always wanted the new thing. Bobbysoxers swooned for Sinatra in the forties because he was the first boy they found to swoon over. French painters and British merchants were hot for Japonisme once the land of the rising sun opened for trade in the middle of the 19th century. New is always good.

But something seemed to happen in the 1960s, presumably as a reaction to the post-war privations and probably thanks to the arrival of a truly global media. At some point between Lady Chatterley's Lover and the birth of The Beatles the new thing became the only thing. We all became neophiles, eager for new sounds, new ideas, new images. A youthquake. And Donovan gave it to us. "For me the sixties stuff is fantastic," says Hillman, who was art director at the celebrated Nova magazine. "And you have to remember it was done in the time when no-one was doing anything like that at all."

Those of us who came later, those of us who are, as Pulp's Jarvis Cocker says, "children of the echo" of that youth explosion, can get resentful of the goldenness of those days; can say, well it wasn't really like that, that the sixties only happened among a few gilded people. But it's hard to look at the sixties images in Terence Donovan Fashion and not be impressed. By their sense of nowness, by their casual brilliance. It's possible that nobody has ever done better men's fashion photography than Donovan. He cast his models as spies, shot them against industrial backdrops, made them look like actors, made them look cool. He clearly liked shooting these images. But it was women he loved to photograph. It was women he loved. Just ask his widow.

In her London home Diana Donovan is surrounded by her late husband's images. His paintings line the wall, his books fill the shelves. There's an image of an impossibly young Cindy Crawford, all piled-up hair and cleavage, by the front door. "Isn't she delicious?" Diana says as we pass it. Diana herself is a very well preserved woman of a certain age (all she will tell me is that she is "over 40") who, 16 years after his death, is still hugely proud of her husband and his work. She met him when she was working as picture editor of Puttnam's financially disastrous but creatively thrilling London Life magazine in the early sixties. Hillman worked on it too.

"The magazine didn't have enough money for models," she says, "so they asked him to take a photograph and they used all the women in the office, and that was the first time I met this godlike person we were all told to watch out for because he came with a reputation, Terence." What reputation was that? "Very powerful, very good photographer. Very demanding. Somebody you had to respect." At the end of the shoot Donovan offered her a lift home, drove her as far as his studio in Knightsbridge and said, "OK, here you are."

"I said, 'This is not where I live.' He said, 'No, but this is where I live, so out you get.'"

She didn't meet him again until years later, not until she was working as a publicist for Woodfall Films. But he'd left an impression. Puttnam reintroduced them in 1968. "It certainly wasn't love at first sight. But he was an extraordinary, interesting man. He was absolutely fascinating. Terence was very powerful, interesting and completely focused. He wasn't going to deviate from what he thought was the right thing to do and that was part of his allure. His extraordinary dedication and focus."

He knew what he wanted? "He certainly did. And he stayed with it. He wasn't easily swayed." She laughs, perhaps at the memory of trying. "We had a fairly lively courtship."

Their backgrounds were very different. She'd been brought up in Guyana, a solicitor's daughter, and been sent to an English convent boarding school. Donovan was older, the son of a lorry driver who would take her to Sunday dinner with his Aunt Doll and Uncle Bill in the East End every Sunday. ("This was the first generation who didn't hide their backgrounds," points out Puttnam.)

They married in 1970. By then he was a huge figure, literally and figuratively ("6ft 6in square" as Hillman recalls), the self-made man who changed his chocolate-coloured Rolls-Royce every three years and sent his secretary out to the tailor Doug Hayward to order three of the same suits, six of the same shirts and three pairs of the same shoes on a regular basis so he didn't have to make a decision as to what to wear of a morning.

By then he'd already remade himself. When Puttnam first met him in the early sixties Donovan was going through a tough time. "He'd been drinking very heavily. He stopped, literally, just like that. He was a big guy. He'd put on a huge amount of weight. So he was struggling with both his weight and coming off the juice and, quite incredibly, I never knew him to take another drink."

With Diana he had two children, Daisy and Terry, and a career that saw him make a film and countless commercials and pop videos. "Driven is not the right word for Terence," says Diana. "He just loved doing what he did. He used to say, 'You need to get up in the morning and do your hobby and get paid for it.'"

She is fiercely protective of him. When I suggest that it's his sixties images I like most she jumps to the defence of his later work. Certainly he never lost his technical acumen. Puttnam feels his style didn't so much develop as harden in the seventies as he did more and more studio work. But as Hillman points out, "He always shocked people. I remember when he did those slightly misty pictures, long before Sarah Moon ever did them, for me in Nova and everyone was taken aback. Some people thought he hadn't focused the camera or something. He was always on the edge and he'd push you as far as he could."

By 1986 that meant dressing up red-lipped, doll-faced models in short skirts and sheer tops to pretend to be Robert Palmer's backing band in the Addicted To Love video. When it came out, it seemed irredeemably sexist to me. How did he deal with that criticism? "Well, it's hard to say," Diana tells me, "because nobody criticised it. It's one of the greatest videos ever. Everybody thought it was absolutely wonderful."

Like I say, fiercely protective. You wonder what her own relationship was with the knowledge that he spent his days with some of the world's most beautiful women? "It's not easy," Diana says, "but you have to approach it intelligently. It's his life. There was no way I was going to stop it and I just had to enjoy it.

"There were occasions when you'd think, 'Crikey, he's going to work with Christy Turlington today and I don't feel so good.' I did the best I could. It didn't turn me off making an effort."

The book is a fashion book but, really, he wasn't so interested in the fashions. It was all about the women wearing them. Or not, as the case may be. Diana goes to the bookshelf to show me his book Glances, a book of female nudes. "You've got to really like them to make them look as beautiful as this," she says as we glance through it. Puttnam agrees. "In the nicest sense he really loved women," he says. "He was completely fascinated by them. I mean, he worshipped Diana."

He also became known for his photographs of another Diana, the Princess of Wales. "One of his great talents was he could talk anybody into doing anything," Hillman says. "There's the famous story of Princess Diana. She was nervous and he said, 'Don't be nervous,' and he took a £20 note out of his wallet, waved it in the air and said, 'Smile at mother-in-law.'" She did. He got the picture. He'd get many more.

There's a circle you can't square in the story of Terence Donovan's life. Why did this emotionally generous, enormously talented man, one who seemed totally at ease with himself, take his own life? At the inquest, it emerged he had been taking steroids to treat a skin condition, and a side effect of the drugs was depression. He was 60 years old, still hard at work and yet he retreated to his studio and killed himself.

"To this day I don't think I've had such a shock," admits Puttnam. "Terry's death came absolutely out of the blue. And I've never really got over it because you end up asking yourself, 'What could I have done? Was there a conversation I should have had?' I don't think I've ever shaken that off. And that really troubles me.

"He's the one person who in my life – other than my father – I actually miss. I physically miss him every week. I wouldn't say every day, but not a week goes by where I don't miss him being around."

His death, even now, is still too raw for Diana to talk about so what, I ask, did Donovan teach her? "I think probably compassion," she says, "and learning to try to understand other people, other people's way of life, point of view. Just being tolerant."

Was that outlook his legacy? "I suppose so. It's just something that one recalls that he was particularly good at and that you want to emulate because you remember that was part of his fabric. And I have these two wonderful children who have been absolutely fantastic in the way they've coped and the way they've managed and you understand about working together as a family, as a unit.

"There's no doubt about it. Something like that changes your life dramatically and you have to adjust and deal with it, so I just hope I've managed to deal with it in the best way I could."

Donovan left roughly a million photographs – negatives, prints, contact sheets – behind. Diana, with the help of former Vogue picture editor Robin Muir and Hillman, has now produced two books to remind us of his talent. Is paying tribute to the photographer as important as paying tribute to the man, I ask her. "The photographer is the man," she replies. You can't separate them? "No. Since he was a little boy developing his photographs in the cupboard with the lightbulb covered in a red rag. That's somebody who is dedicated. This book is really a tribute to his work as a fashion photographer. In a way it's inadequate because there's so much more, but it's the best David Hillman and I could do. These are the pictures we liked, that we loved, that we thought showed the best of Terence Donovan."

Maybe. Or maybe that's to be found in the memories of his friends and family. For the rest of us there are the images, the best of them as fresh and new as they day the shutter clicked.

Terence Donovan Fashion, edited by Diana Donovan and David Hillman with a text by Robin Muir and foreword by Grace Coddington, is published by Art/Books, priced £60. Visit www.artbookspublishing.co.uk.