Charles of Arnulf, traditionally b. 2 April 742, d. 28 January 814, became known as Charlemagne in later years, this name derived from the French "Carolus Magnus" or Charles the Great.Charlemagne was thrust into the world of imperial leadership when his father, Pepin the Short, was recognized by Pope Zachary as King of the Franks. Shortly after his accession, Charles acquired the territories of his brother Carloman and set out to unify Europe under the Frankish crown. By 785 he had subdued both Christian and pagan armies and on Christmas Day in 800, the pope crowned him Emperor in the Roman fashion-- to the consternation of the Byzantine emperor, who claimed the title in East and West alike.