Elizabeth came to the throne in 1952, at the age of 25. She is a descendant of the House of Saxe-Coburg and Gotha, which was renamed the House of Windsor during the First World War. Queen Elizabeth married Prince Philip on 20th November 1947, almost 68 years ago. They have four children, the oldest of which, Prince Charles, is next in line to the throne.
Prior to 9th September, the longest reigning monarch in the UK was Queen Victoria, who ruled for 63 years, seven months and two days. Victoria became Queen when she was only eighteen years old, and ruled until her death. Queen Victoria took over the claim to being the longest reigning monarch from King George III, who ruled from 1760 until 1820.
Of course, there have been many changes since Victoria ruled Britain. When she came to the throne there were approximately 16 million people living in England, Scotland and Wales. By contrast, when Elizabeth II assumed the crown, England and Wales alone inhabited 50 million. When Elizabeth celebrated her Diamond Jubilee in 2013, that population had increased to in excess of 63 million.
During her reign, Queen Victoria saw 10 British prime ministers come and go. In contrast, Queen Elizabeth has already witnessed the rise and fall of 12 prime ministers.
Queen Victoria, who also had the title of Empress of India, inherited the now dissolved British Empire, whereas Queen Elizabeth II became head of the Commonwealth. Over the course her reign, the Queen has visited 116 of her Commonwealth countries, travelling approximately 43,600 miles between them in 1953 on her coronation tour alone.
Celebrations in honour of the Queen are to be held all over the Commonwealth. The Royal Mint has issued a special coin to commemorate the event, and television, radio, school, and community events are also being held across Britain to mark it.
Dr Kathryn Bates is a graduate of archaeology and history. She has excavated across the world as an archaeologist, and tutored medieval history at Leicester University. She joined the administrative team at Oxford Open Learning twelve years ago. Alongside her distance learning work, Dr Bates is a bestselling novelist, and an itinerant creative writing tutor for primary school children.