George William Frederick, commonly known as King George III, was the King of Great Britain and Ireland from 1760 until 1820. He was born on June 4, 1738, and became king at the age of 22. His reign is noted for significant events, including the American Revolutionary War and the expansion of the British Empire. George III faced various challenges during his rule, including political unrest and mental health issues later in life. He was a member of the House of Hanover and is often remembered for his long reign and the impact it had on British history and its colonies.