Charlemagne (pronounced ; Latin: Carolus Magnus or Karolus Magnus, meaning Charles the Great; possibly 742 – 28 January 814) was King of the Franks from 768 and Emperor of the Romans (Imperator Romanorum) from 800 to his death. He expanded the Frankish kingdom into an empire that incorporated much of Western and Central Europe. During his reign, he conquered Italy and was crowned Imperator Augustus by Pope Leo III on 25 December 800. This temporarily made him a rival of the Byzantine Emperor in Constantinople. His rule is also associated with the Carolingian Renaissance, a revival of art, religion, and culture through the medium of the Catholic Church. Through his foreign conquests and internal reforms, Charlemagne helped define both Western Europe and the Middle Ages. He is numbered as Charles I in the regnal lists of France, Germany (where he is known as Karl der Große), and the Holy Roman Empire.
The son of King Pepin the Short and Bertrada of Laon, he succeeded his father and co-ruled with his brother Carloman I. The latter got on badly with Charlemagne, but war was prevented by the sudden death of Carloman in 771. Charlemagne continued the policy of his father towards the papacy and became its protector, removing the Lombards from power in Italy, and leading an incursion into Muslim Spain, to which he was invited by the Muslim governor of Barcelona. Charlemagne was promised several Iberian cities in return for giving military aid to the governor; however, the deal was withdrawn. Subsequently, Charlemagne's retreating army experienced its worst defeat at the hands of the Basques, at the Battle of Roncesvalles (778) memorialised, although heavily fictionalised, in the Song of Roland. He also campaigned against the peoples to his east, especially the Saxons, and after a protracted war subjected them to his rule. By forcibly converting them to Christianity, he integrated them into his realm and thus paved the way for the later Ottonian dynasty.
Today he is regarded not only as the founding father of both French and German monarchies, but also as the father of Europe: his empire united most of Western Europe for the first time since the Romans, and the Carolingian renaissance encouraged the formation of a common European identity.