When historians come to write about the loss of Diana, Princess of Wales, they are likely to focus not only on the tragedy but on an apparently minor event that happened at 10:45 a.m. London time on Saturday.
At that precise moment, the British flag - the red, white, and blue Union Jack - was lowered to half-mast above London's Buckingham Palace.
A casual observer might have thought something routine was taking place. In fact, the flag and its position on the flagstaff symbolized a historic turning point for the troubled British monarchy and its relationship with the people of Britain. It was the first time the Union Jack had ever flown over a royal residence.
Anthony Holden, an acclaimed royal biographer, observed: "Things can never be the same again. The queen has been forced to bow to the will of the people. For centuries, it has been the other way around."
In the past, when Britain's monarchs were in residence anywhere, the lemon-colored royal standard - their personal flag - was flown wherever they happened to be staying. When they moved elsewhere, it was always hauled down. Inflexible royal protocol was involved. It was part of the mystique of monarchy.
The funeral service offered further evidence that, unless they change their ways, Britain's royal family and the institution of monarchy face a stormy, uncertain future in which people power is now evidently part of the fabric of British life.
Against all precedent, and with barely restrained anger, Diana's brother, Earl Spencer, in a funeral tribute, came within an inch of lecturing the queen on how the two princes should be brought up.
Proclaiming the rights of the Spencer "blood family," he said that instead of making "duty and tradition" the basis of their upbringing, the two boys should be allowed to "sing openly" as their mother had planned.
In the British media the earl's remarks were almost universally seen as a public rebuke to the royal family which, he recalled, had stripped Diana of her royal title.
But it was not the Spencer tribute that must have given Queen Elizabeth most to think about. Just as when the Union Jack was lowered to half mast at Buckingham Palace the crowds burst into loud applause, people outside Westminster Abbey began clapping and cheering at the end of Earl Spencer's speech. The applause could be heard through the open doors of the abbey and seemed to roll inside as the entire congregation of 2,000 began clapping too.
The crowds seemed to be saying that the days of stiff upper lips and royal protocol are over, and that if it wants the loyal support of the public, the monarchy must get itself in tune with the people. There could hardly have been a clearer message for the queen and the rest of the already buffeted House of Windsor.