Charles III (839 – 13 January 888), also known as Charles the Fat, was the emperor of the Carolingian Empire from 881 to 888. A member of the Carolingian dynasty, Charles was the youngest son of Louis the German and Hemma, and a great-grandson of Charlemagne. He was the last Carolingian emperor of legitimate birth and the last to rule a united kingdom of the Franks. Usually considered lethargic and inept—he was frequently ill, and is believed to have had epilepsy—Charles twice purchased peace with Viking raiders, including at the infamous Siege of Paris which led to his downfall.