At Kensington Palace, the focus of mass public mourning in 1997, loyal fans returned with flowers and candles, though in dwindling numbers.
``She did so much for the nation that coming down here on this day I just feel inside that I have given something back,'' said Ann Woodhouse, 56, who made a special trip to the palace from her home in the northwest England city of Liverpool.
``The hierarchy have forgotten Diana, but we are never going to forget,'' said Julie Kain, 35, of Newcastle.
At Westminster Abbey, where Diana's funeral service took place, the princess was to be remembered in prayers.
Prince William, Diana's 18-year-old son who just graduated from Eton, was away from home on Thursday's anniversary. He went to Belize right after school to begin a year of traveling and working before starting college.
Prince Harry, 15, was with his father, Prince Charles, at Balmoral, the royal family's private estate in the Scottish Highlands. It was at Balmoral, on Aug. 31, 1997, that William and Harry first heard of their mother's death.
On Sunday, Charles and Harry were with Queen Elizabeth II, Prince Philip and the 100-year-old Queen Mother Elizabeth at Crathie Church, Balmoral. Prayers were said for Diana, although she was not mentioned by name, as is traditional in the Church of Scotland.
Althorp, the Spencer family estate, closed its doors to the public Wednesday after its two months open each year for people to visit a memorial to Diana by her brother, Earl Spencer. The earl was expected to spend the anniversary quietly at Althorp, where Diana was buried on an island in an ornamental lake.
A memorial was planned Thursday at Harrods, the London department store owned by Mohamed Al Fayed, whose son Dodi died in the Paris crash with Diana.
Al Fayed said Wednesday he will file suit in U.S. federal court to gain access to American intelligence information, and repeated his claim that Diana and his son were victims of a murder conspiracy plotted by people who disapproved of their relationship.
He said he was seeking documents from the CIA, the Justice Department and the National Security Agency.
``No one suspects the U.S. government was involved'' in the accident, said Al Fayed's lawyer, Mark Zaid. But he said the government might be withholding information.
Neither Justice Department spokesman Charles Miller nor NSA spokeswoman Judi Emmel would comment, citing the pending litigation.
CIA spokesman Mark Mansfield said the agency understands Al Fayed's ``grief and tremendous sense of loss.'' But he said any suggestion that the CIA spied on Dodi Fayed or on Diana, or that it knows of any plot to murder them is ``totally unfounded.''
In April, an appeals court rejected Al Fayed's request for the information, upholding the decision of a lower court judge who said Al Fayed had tried ``to make an end run around'' the Freedom of Information Act.
Paris judge Herve Stephan has concluded that alcohol, drugs and excessive speed caused the crash that ended the life of the ``people's princess.''
In the past three years, the Diana, Princess of Wales Memorial Fund has amassed $160 million from public donations, corporate and other funds and the licensing of Diana memorabilia.
So far, $40 million has been pledged to help the most disadvantaged people. A total of $65 million will be spent by 2001, then $10 million each year thereafter.