Elizabeth II to become Britain's longest serving Monarch

Queen Elizabeth II will today become the longest-reigning monarch in British history, but she doesn't take the title on a global scale. Here's a look at some long-term throne-sitters.

Queen Elizabeth II (AAP) Source: Press Association

Queen Elizabeth II became the longest-ruling British monarch on September 9, overtaking her great-great grandmother Queen Victoria.

Victoria was the head of the British Empire for 63 years, seven months and two days (23,226 days), from June 20, 1837 until her death on January 22, 1901.

Victoria was only 18 years old when she took the throne, her great-great granddaughter Elizabeth was 25 when she became Queen of the United Kingdom.

The next longest-serving British monarch was King George III.

Note: Llywelyn was a Prince of Wales, but was the de facto ruler. Dates for his rule are approximate.

While Elizabeth II will become the longest-serving British monarch in September, her experience has been and will continue to be different from Victoria’s.

In Victoria’s time the British Empire was experiencing growth, partly through the supremacy of its Royal Navy and the effects of the Industrial Revolution.

The size of the British Empire peaked in the early 20^th century – the largest empire the world had ever seen – before Elizabeth II became Queen in 1952.

Source: Wikipedia

Map: the world in 1897, with British 'possessions' coloured in red.

While Queen Elizabeth II will become the longest-serving British monarch, there's another monarch who is older.

King Bhumibol Adulyadej of Thailand is the longest-serving living monarch, having served as King since June 9, 1946.

Other long-serving monarchs include the Sultan of Malaysia's Kedah state, Sultan Abdul Halim Mu'adzam Shah and the Sultan of Brunei, Hassanal Bolkiah.

There are deceased monarchs who held their thrones even longer.