THE Queen Mother has died, Buckingham Palace have announced with her daughter, her majesty the Queen, at her bedside.

The 101 year-old died "peacefully in her sleep" on Saturday afternoon at Royal Lodge, Windsor, the Palace said.

"Queen Elizabeth the Queen Mother had become increasingly frail in recent weeks following her bad cough and chest infection over Christmas," said a Palace spokesman.

"Her condition deteriorated and her doctors were called. Queen Elizabeth died peacefully in her sleep at 3.15pm."

Her coffin is expected to be moved to the Royal Chapel of All Saints in Windsor Great Park.

Her death came six weeks after her last public appearance when she attended the funeral of her daughter Princess Margaret.

She had outlived her husband King George VI by 50 years and had become a much-loved national institution.

Before the funeral the nation will be able to pay homage to her when she lies in state in the medieval setting of Westminster Hall.

The Prince of Wales, Prince William and Prince Harry were described as "completely devastated" after being informed of the death while skiing.

Charles was told first as he returned from the slopes at Klosters to his hotel.

William and Harry found out later as they had skied to the last lift of the day. They were told by their father who ushered them into his bedroom at the Walserhof.

Charles and his sons will fly back to Britain on Sunday, when royal advisers will meet to finalise details of the Westminster Abbey service.

Tony Blair tonight led the tributes to the Queen Mother, saying she had been a symbol of Britain's "decency and courage".

The Prime Minister said that the entire nation would join with the Queen and the Royal Family in mourning her death.

Mr Blair continued: "She was part of the fabric of our nation and we were immensely proud of her.

"Along with her husband, King George VI, she was also a symbol of our country's decency and courage.

"Her bravery when she refused point blank to leave London and her husband's side during the Blitz epitomised both her own indomitable spirit and the spirit of the nation in its darkest hours."

Floral tributes to the Queen Mother have begun arriving at Buckingham Palace. The gates at the royal residence have been cordoned off.

Tiny lit candles, St George's flags and bouquets have all been put in front of the gates.

One tribute written on a card left on the lawn said: "I really don't know what to say, our nation lost its grandmother today."

At Windsor Castle, scores of people gathered to pay their respects.

As darkness fell, people outside her official London residence Clarence House recalled the Queen Mother's resilience during the war.

The Queen Mother's last public engagement had been on November 22 when she re-commissioned the aircraft carrier Ark Royal at a ceremony in Portsmouth, Hampshire.

But despite her illness she flew by helicopter from Sandringham to Windsor to attend the funeral of Princess Margaret who died on February 9 after suffering a stroke.

The Queen Mothers life in pictures...click here