The Queen is marking the 55th year of her accession to the throne privately at Sandringham.
The Queen does not celebrate the day of her accession
She has returned to the royal estate in Norfolk after a one-day official visit to the Netherlands.
Her father, King George VI, died at Sandringham on 6 February, 1952 - after suffering from lung cancer - while Princess Elizabeth was in Kenya.
The Queen heard of her accession while at the Sagana Hunting Lodge, in the foothills of Mount Kenya.
The King's Troop will fire a 41-gun salute in Hyde Park and a 62-gun salute will be carried out at the Tower of London by the Honourable Artillery Company.
The Queen will return to Buckingham Palace on Wednesday after being in residence at Sandringham since before Christmas.