Royal Family, Richard Cawston's documentary which attracted audiences of 22 million and 15 million on the BBC and ITV in 1969, was intended to usher in a new age of openness for the Royals. It showed them as they lived; talking to each other, having a barbecue at Balmoral and doing good works.
But some feel that the two hours of scripted informality whetted the public's appetite for more and more information, and led to the kind of overbearing attention from photographers which preceded Saturday night's car crash.
Princess Diana's life in the public glare and the manner of her death makes a complete circle. For most people their first memory of her is of a young blonde woman running down the Brompton Road in west London trying to get away from photographers and into her Mini. If Diana had been chosen as royal consort with half an eye on the media's response, she seemed to have been the perfect choice.
The public were sold on the fairy-tale wedding story and the press knew that putting Diana on the front page would shift papers. But the fierce circulation war at a time when newspaper-reading was falling meant that the fairy-tale story wasn't strong enough to sustain the tabloids as it might have been for earlier generations of Royals.
When the marriage started disintegrating both parties tried to use the media to hold on to the public's sympathy. This ambiguous relationship with the press will haunt any simple attempt to blame the media for her death.
In 1993 Sir David Calcutt's report into invasion of privacy by the press was blown apart by the revelations that large sections of the establishment were well aware that Princess Diana and Prince Charles, or their friends, were briefing their own favoured newspapers with their side of the marriage break-up.
Lord MacGregor, then the chairman of the Press Complaints Commission, was forced to conclude that the intrusions into "the private lives of the Prince and Princess of Wales were intrusions contrived by the Princess herself and her entourage". He also pointed out: "The Princess had, in practice, invaded her own privacy.''
This included giving authorisation to her friends to talk to Andrew Morton for his book Diana: Her Own Story in which it was revealed that she had attempted suicide and was suffering from bulimia.
The young woman who once allowed a photographer to take a shot of her with the sun streaming through her skirt became photography's consummate manipulator. Her lonely pose in front of the Taj Mahal on a trip to India in 1992 was a piece of propaganda genius. But stunts like that made the public sceptical when she announced in December 1993 that she was retiring from public life.
Her relationship with the press was further complicated by the close nature of her friendship with the Daily Mail. Sir David English, editor- in-chief of the Mail, acted as an informal adviser to the Princess and she conducted a number of secret liaisons with the Mail reporter Richard Kay who became a confidant.
Yet at the same time Diana could be driven to distraction by the constant watch kept on her. In 1993 she went to court to prevent the Daily Mirror printing photographs of her exercising in her gym, and on a skiing trip in 1994 she accused press photographers of "raping her".
Last year she obtained an injunction against a freelance photographer, Martin Stenning, accusing him of harassing her. It became clear that some photographers were treating Diana as their only assignment.
Ultimately it was the side of her that wanted privacy and to escape the photographer's lens that caused her death. On another day, in another frame of mind, it could have been a very different story.
Diana: death of a PR dream Media+, The Tabloid