King George IV of the United Kingdom reigned from 1820 to 1830. He was the eldest son of King George III and became king after his father's long and troubled reign. Known for his extravagant lifestyle, George IV was a patron of the arts and played a significant role in the development of Regency architecture. Before becoming king, George IV served as the Prince Regent from 1811 due to his father's mental illness. His reign was marked by political unrest and the growing demand for reform, including the push for the Reform Act that aimed to change the electoral system in Britain.