11. George III
By Workshop of Allan Ramsay – Unknown, Public Domain, https://commons.wikimedia.org/w/index.php?curid=1621850
George III became King of Great Britain and Ireland in 1760. He ruled until the countries united in 1801, when he became King of the United Kingdom.
There, he ruled until he died in 1820. He was a member of the House of Hanover, and he ruled for a longer period of time than any preceding monarch in Britain.
During George’s rule, Great Britain had defeated France during the Seven Years’ War
Soon, Britain also lost American colonies due to the Revolutionary War.
Unfortunately, the latter part of George’s rule was marred by mental illness.