Here are some statistics to mark the Queen becoming the longest-serving monarch in British history:
33,446,430 minutes - approximate length of Elizabeth’s II reign when she sets the new record at around 5.30pm on September 9 2015. This works out as 23,226 days, 16 hours and 30 minutes.
12 - prime ministers who have served Elizabeth II since she became the Queen. The first was Winston Churchill (1951-55); the latest is David Cameron (2010 to date).
10 - hours the Queen has spent reading out speeches at the State Opening of Parliament. She has delivered the speech in person 62 times.
7 - Archbishops of Canterbury to have served the Queen. The first was Geoffrey Fisher, who presided at the marriage of Princess Elizabeth in 1947 and at her coronation in 1953. The others have been Michael Ramsey, Donald Coggan, Robert Runcie, George Carey, Rowan Williams and Justin Welby.
97 - state visits the Queen has undertaken so far. Her first was to Norway in June 1955. Her most recent was to Germany in June 2015.
173 - visits by the Queen to Commonwealth countries. Her first was to Kenya, where she learned she had become Queen on February 6 1952. Her most recent was to Australia in October 2011.
2 - countries that have left the Commonwealth during the Queen’s reign: Zimbabwe (in 2003) and the Gambia (in 2013).
0 - passports the Queen has held. She has no need for one, as all British passports are issued in her name.
2 - self-governing territorial possessions of the Queen, known as Crown dependencies. There are two: the Channel Islands and the Isle of Man. Neither is part of the UK, but the British government is responsible for the defence and international relations of the dependencies.
36 - Royal Variety Performances the Queen has attended. In recent years the Duke and Duchess of Cornwall and the Duke and Duchess of Cambridge have represented the royal family.
56 - televised Christmas messages delivered by the Queen. Her first was transmitted live in 1957, while the first pre-recorded TV message was in 1959. There has been a televised message every year since 1957 except in 1969, when a repeat of the film Royal Family was shown.
109 - state visits hosted by the Queen. The first was a visit by King Gustaf VI andQueen Louise of Sweden in June 1954. The most recent was a visit by the president of Mexico Enrique Pena Nieto and his wife Angelica Rivera de Pena in March 2015.
50,000 - number of people the Queen hosts in an average year at banquets, lunches, dinners, receptions and garden parties at Buckingham Palace.
67 - years the Queen and the Duke of Edinburgh have been married. They will celebrate their 68th wedding anniversary on November 20 2015.
6 - years the Queen ranks behind the world’s longest-serving current head of state, King Bhumibol Adulyadej of Thailand. He has reigned since June 9 1946 and is 87 - two years younger than the Queen.