George William Frederick was born on June 4, 1738 in London, the son of Frederick, Prince of Wales and of Augusta, Princess of Saxe-Gotha-Altenburg.
He took over from his grandfather George II as King of the United Kingdom and King of Ireland in 1760, then became King of the United Kingdom of Great-Britain and Ireland in 1801. On the other hand, he was Elector of Hanover from 1760 to 1814, then King of Hanover from 1814 to 1820.
On September 8, 1761, in St James's Palace, George III married Princess Charlotte of Mecklenburg-Strelitz, who gave him fifteen children.
Unfortunately the later part of his reign suffered from his illness (a mental alienation probably due to the blood disease porphyria), and his eldest son, the Prince of Wales, had to rule the kingdom as Prince Regent from the year 1811.
George III died on January 29, 1820 at London.