A NATION united to honour the Queen Mother as three generations of the Royal Family joined a parade carrying her coffin through London.

Thousands of people were bathed in glorious sunshine as they turned out to pay their final respects to the royal icon, marking the greatest ceremonial procession for a generation.

A poignant message from the Queen -- a card reading simply "In loving memory, Lilibet" was placed in top of the coffin as it made the journey from St James's Palace to Westminster Hall.

Amid all the pomp and splendour, it was a reminder of the Queen's personal sense of loss after her mother's "wonderful life".

The Duke of Edinburgh, Prince Charles and Princes William and Harry were among 14 senior royals accompanying the coffin to Westminster Hall where it will lie in state until the funeral on Tuesday.

The teenage princes, bare-headed and dressed in morning suits, in contrast to other family members in their military uniforms, were taking part in the second royal funeral procession in their short lives.

Shortly before 11.30am the Queen Mother's coffin, draped in her personal standard and surmounted by her diamond-encrusted crown, was carried from the Queen's Chapel at St James's Palace and placed on a horse-drawn gun carriage.

The Royal Family were immediately behind the coffin, followed by members of the Queen Mother's personal staff.

The Mall rang to the sound of military bands and marching boots in the build up to the funeral procession.

Then a gun salute from Green Park thundered across the capital and troops, with rifles reversed, marched with music at 116 paces to the minute

The Queen, dressed all in black, arrived at the Palace of Westminster by car as a military band played the National Anthem in Parliament Square.

The Archbishop of Canterbury, Dr George Carey, and the Lord Chancellor, Lord Irvine, were among the party who greeted her.

From across the UK and around the world, people gathered to witness the pomp and pageantry.

Some camped overnight, many more began arriving at dawn to secure a good view.

Not since Sir Winston Churchill was laid to rest in 1965 or the Queen Mother's husband King George VI passed away in 1952 has there been a military spectacle of greater calibre.

The Queen Mother's platinum crown was created by royal jewellers Garrard for the Queen Consort at the Coronation of 1937 and is usually kept behind armoured glass at the Tower of London.

Among the more than 2,800 diamonds in the crown is the priceless 105.60-carat Koh-i-Noor stone which was brought to England in 1850 after the annexation of the Punjab during the British Raj in India.

The Queen Mother's funeral will be followed by a private committal service and interment next to her husband in the George VI Memorial Chapel within St George's Chapel at Windsor later that day.

The funeral at the Abbey is expected to be witnessed by a congregation of 2,100 people, including up to 25 foreign Royals and heads of state, and surviving celebrities from the Queen Mother's era.