The Queen has led the tributes to royal photographer Lord Lichfield, after his death from a stroke at the age of 66.
Lord Lichfield was the Queen's first cousin once removed
She said she was "deeply saddened" at news of the death of her cousin.
Lord Lichfield was well-known for his photographs of the wedding of the Prince of Wales to Princess Diana and of a string of celebrity subjects.
Baroness Thatcher, photographer Terry O'Neill and actress Britt Ekland were also among those to pay tributes to the renowned portraitist.
Lord Lichfield had been admitted the stroke unit at the John Radcliffe Hospital in Oxford after falling ill while staying with friends in the area. He died at 0400 GMT on Friday.
A Buckingham Palace spokeswoman said: "It's a private matter. The Queen is deeply saddened and will be sending private condolences."
Lord Lichfield - who inherited the earldom of Lichfield in Staffordshire from his grandfather - was perhaps best-known for a single informal shot at the wedding of Prince Charles and the then Lady Diana Spencer.
He also photographed the Queen - to whom he was a cousin once removed - and the Duke of Edinburgh for their Golden Jubilee in 2002.
Lord Lichfield first became a photographer in the 1960s having spent time in the Army.
Iconic images of singer Marsha Hunt, artist David Hockney and actor Michael Caine helped cement his reputation as one of the country's foremost photographers.
He also photographed nudes for the annual Unipart calendar.
Even though he was in his 60s, Lord Lichfield continued to be prolific.
He recently photographed Baroness Thatcher for her 80th birthday.
Lord Lichfield was impeccably connected
She said: "Patrick Lichfield was not only one of the most talented and professional of photographers, he was also an absolute delight to sit for.
"Always courteous and considerate, he had a rare skill which is now sadly gone."
Actress Britt Ekland, who posed for Lord Lichfield in 1970 and again two years ago, said: "I am deeply shocked and surprised by his death. Lord Lichfield was a wonderful photographer."
Friend and photographer Terry O'Neill said Lord Lichfield's style was always spontaneous.
"He did go for the moment. He was instinctive. It was part of his nature."
He remembered that the aristocrat liked to be viewed as "one of the chaps".
Tatler editor Geordie Greig said Lord Lichfield was an "old-fashioned gentleman".
He said: "The royal wedding was spectacularly memorable, he got the intimacy of the Royal Family, he got that fairytale magic.
"There was a sort of almost Hollywood magic dust spread throughout that shoot and the world enjoyed it.
"He wasn't complicated, he wasn't pretentious, he wasn't an intellectual, he just loved making beautiful images."
As well as editorial photography, he worked on advertising commissions across several industries, including fashion, tobacco and pharmaceuticals.
He was recently commissioned by the British Tourist Authority, and was involved in Hot Shots, a television series for Discovery Real Time in which amateur photographers are taught by professionals.
Interviewed in October by the BBC News website, he told reporter Caroline Briggs: "Remember that the person you are photographing is 50% of the portrait and you are the other 50%.
"You need the model as much as he or she needs you. If they don't want to help you, it will be a very dull picture."
Lord Lichfield's long-term partner was Lady Annunziata Asquith, and he had had three children with ex-wife Lady Leonora Grosvenor - a son, Tom, and two daughters, Rose and Eloise.