Louis the German. Charles III the Fat, sometimes called Charles II of France, was the son of Louis the German and grandson of Charlemagne. Born in 839, Charles III the Fat was a Frankish king and emperor. His fall in 887 marked the final disintegration of the empire of Charlemagne. He was the youngest son of Louis the German and was crowned emperor by Pope John VIII in 881 and became king of all the East Franks in 882, succeeding his brother Louis the Younger. Charles III the Fat died on January 13, 888.