"Memoirs of the Reign of King George the Third" in 4 volumes are a historical account written by Horace Walpole that comprises the first twelve years of the reign of George III. George III (c. 1738-1820) was King of Great Britain and King of Ireland from 1760 until the union of the two countries in 1801, after which he was King of the United Kingdom of Great Britain and Ireland until his death in ...