LONDON -Today promises to be a sunny one for the grand street procession that will accompany the Queen Mother's coffin from St. James's Palace to Westminster Hall: the largest event of its kind since the funeral of Sir Winston Churchill four decades ago.

But it will be a traumatic day for her great-grandsons Prince William and Prince Harry, a grief-filled one for her grandson the Prince of Wales, and a lonely one for her daughter the Queen.

The two young princes will walk behind the Queen Mother's coffin during the 28-minute journey, along with 12 other senior members of the Royal Family. They will be flanked by some 1,600 members of the military, including the Toronto Scottish Regiment and two other Canadian regiments.

For the princes the day will undoubtedly bring back memories of a similar one five years ago, when the two despondent schoolboys followed the body of their mother Diana, Princess of Wales, along a packed procession route filled with thousands of mourners.

The Queen Mother's procession is expected to be less dramatic and less well attended. No official holidays have been declared for the event, or for her funeral on Tuesday. And although many of Britain's 60 million people feel affection and respect for the woman who was a symbol of their country's spirit during World War II, her advanced age has smoothed the sharp emotional edge her death would otherwise have had.

Yesterday the Queen, looking pale and dressed in black, came out in public for the first time near the royal estate at Windsor, telling some onlookers her mother had had a long and happy life.

"My mother lived to 101, which is a great age," she said to mourners gathered on the lawn outside St. George's Chapel. "She had a wonderful life."

The Queen and Duke of Edinburgh walked around the garden, where well-wishers had left hundreds of floral tributes and notes of sympathy. "She's had a terrible time in these last weeks, and she just came out to talk to people who felt a lot of sympathy for her," one local woman told the BBC, after giving condolences to the Queen.

The Queen Mother is the last of the Queen's close relatives to die. Her younger sister, Princess Margaret, died suddenly less than two months ago, and her father, King George VI, to whom she was very close, passed away when she was in her 20s.

Prince Charles is also said to be deeply affected by his grandmother's death, and has withdrawn in grief, even from other members of the family.

For the royals, today's procession will be a cathartic event. As the Queen Mother's coffin leaves St. James's Palace it will be covered in her standard, and topped by the crown she wore to her husband's coronation, a national treasure containing the fabulous Koh-i-Noor diamond.

Yesterday, British soldiers polished the ceremonial gun carriage that will bring the coffin to Westminster Hall, and spent the day grooming horses and sprucing up formal parade gear for the event. They will be accompanied in the procession by the Toronto Scottish Regiment, members of the Canadian Forces Medical Services and the Black Watch, also known as the Royal Highland regiment.

Before dawn yesterday, the Canadians turned out to rehearse in semi-darkness, along with their British, South African, Australian and New Zealand counterparts. At the same time, some 300 technicians worked feverishly to ready Westminster Hall for the four-day lying in state, which will end with the Queen Mother's funeral Tuesday.

As the procession begins today, shortly after 11 a.m., the Buckingham Palace detachment of the Queen's Guards will take up positions at Westminster Hall awaiting the arrival of the coffin. Meanwhile the other military detachments, including the Canadians, will form up close to St. James's Palace, in central London. There the Queen Mother's coffin will be carried from the Queen's Chapel by Irish Guards, who will place it in the ceremonial gun carriage near the entrance to the chapel.

In the gardens near Westminster Hall there will be places designated for floral tributes from the public, and books of remembrance will be set out. The hall will be open for mourners to pay their respects as the Queen Mother's body lies in state, starting from 2 p.m. today.

Although the crowds at the procession and lying in state are expected to be smaller than those that mourned Diana, there are signs public interest is still running high.

Souvenir shops and stalls in central London were empty of "Queen Mum" memorabilia and bookstores were eagerly awaiting new biographies that are already set to sell out.