Following the death of Thai king Bhumibol Adulyadej, Britain's Queen Elizabeth II has become the world’s longest-reigning monarch at 64 years.
King Bhumibol, who died on Thursday, reigned for 70 years after assuming the throne at the age of 18.
Here is an updated list of the world's other longest-serving monarchs.
Britain’s Queen Elizabeth II, born on April 21, 1926, inherited the throne on February 6, 1952 following the death of her father, king George VI. On September 9, 2015, Elizabeth's reign surpassed that of her great great grandmother, Victoria, who was on the throne from 1837 until 1901. Elizabeth is also queen of 15 other Commonwealth states.
Brunei’s Sultan Hassanal Bolkiah, 70, is one of the richest people on the planet. Born on July 15, 1946, Bolkiah has reigned over the small enclave on the north coast of Borneo since his father abdicated in October 1967. Brunei has sizeable petroleum reserves.
Oman’s Sultan Qaboos, 75, took the throne on July 23, 1970 after ousting his father for allegedly being too conservative. Qaboos has set about reforming the small sultanate, which with Iran controls the strategic Strait of Hormuz, but his health is failing and he has no designated heir. Since 2014, he has been hospitalised several times in Germany.
Denmark’s Queen Margrethe II, 76, became head of Europe's oldest kingdom on January 14, 1972 following the death of her father, Frederik IX. She was born on April 16, 1940.
Sweden’s King Carl XVI Gustaf, who turned 70 in late April, succeeded his grandfather, Gustaf VI Adolf, in September 1973. He and Queen Margrethe are first cousins.
In Europe, the longest verified reign in history is that of French king Louis XIV (72 years between 1643 and 1715). Austrian emperor Franz Joseph I reigned for 67 years between 1848 and 1916.
