By Vanessa Barford
The media became obsessed with photos of Princess Diana
The Queen has warned newspapers not to publish private pictures of the Royal Family, but from Princess Diana to Kate Middleton, the Royals have always been a prime target for the paparazzi.
No member of the Royal Family has captured the attention of the press - and the heart of the public - more than Princess Diana.
Even before her engagement, Diana became a press obsession.
Then came the fairy-tale wedding, the altruistic charity work, the fashionable attire. A photo opportunity would push paper sales through the roof.
The Princess of Wales frequently complained she was harassed.
But Diana's relationship with the press was complicated, at times courted.
Her revelations about her relationship with Prince Charles in a BBC Panorama programme - where she said there were "three in her marriage" and admitted an adulterous affair - were unprecedented.
The frank admission of her battle against depression and bulimia, in the same interview, also ruffled feathers in the Royal Family.
But it was her death after a car crash in Paris in 1997 - and the role of the pursuing paparazzi - that brought allegations of press invasion to the fore.
Parallels have been drawn between Princess Diana and Ms Middleton
Since then the Royal Family has become much more vocal about criticising the media. The press has also been subject to more intense scrutiny.
In 2007, Prince William voiced concern after his girlfriend Kate Middleton was hounded by the paparazzi on her 25th birthday outside her London home.
As a result The Sun, Times, Sunday Times and News of the World vowed not to use paparazzi shots of Miss Middleton.
It followed a request from her lawyers for the press to respect the privacy of Miss Middleton and her family.
They argued that photographers had followed her almost every day and night since she had left university.
The treatment of Kate Middleton has drawn parallels with that of Princess Diana.
In 2007, Miss Middleton settled a complaint against the Daily Mirror, over a close-up photograph of her walking to work.
The paper apologised and admitted its error, but the incident prompted the Press Complaints Commission (PCC) to issue a warning over the treatment of the prince's girlfriend.
But the issue of royal privacy returned in October 2007, when pictures of Prince William and Miss Middleton leaving Boujis nightclub in London were printed in the London Evening Standard.
Clarence House said the prince was "left concerned" after he and Miss Middleton were "aggressively" pursued by at least seven photographers on motorbikes and in cars.
Sandringham House sits on 8,000 acres of land in Norfolk
The incident occurred during the week in which the inquest into the prince's mother's death opened.
The inquest later ruled that the princess and Dodi Fayed were unlawfully killed as a result of the actions of their driver, Henri Paul, and the pursuing paparazzi.
It led to a call from the chairman of the Commons Culture, Media and Sport Select Committee to the PCC, asking the watchdog to ensure the media did not harass royals.
The latest warning, by the Queen's lawyers, is intended to remind papers of privacy obligations under their own code of practice.
Photographers have been told they will be monitored on public roads around the Sandringham estate in Norfolk this Christmas.
In the past freelance photographers have spent many hours touring Sandringham and Balmoral, the Queen's Scottish estate, to try to "snatch" pictures of the family.
Some of the images taken by paparazzi have been seized on by animal protection groups to suggest the Royal Family are cruel to animals, according to The Telegraph.
The paper claims the Queen had been photographed wringing the neck of a wounded pheasant, while the Earl of Wessex had been snapped apparently raising a shepherd's crook to one of his dogs during a shoot.
The Royal Family has reluctantly turned a blind eye to such photographs in the past, provided they were taken from public roads and they did not involve trespass on private land.
But Prince Charles' spokesman said the Royal Family had a right to privacy during "everyday private activities".