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 saw significant events, including the American Revolutionary War, which led to the loss of the American colonies. George III is often remembered for his struggles with mental health, which affected his ability to rule. Despite these challenges, he was a dedicated monarch who worked to strengthen the British monarchy and promote agricultural and economic reforms during his reign.