CharlemagneCharles the Great 742 CE to 814 CE - The oldest son of the King of the Franks, Pepin the Short. After the death of Pepin, Charlemagne became co-ruler with his brother, Carloman I. In the following years Carloman passed away leaving Charlemagne to be the sole king. He forged an alliance with the papacy and helped conquer the Lombards to remove them from power in Italy. He also led a campaign against the pagan Saxons. His efforts led to pope Leo III declaring him the Emperor of the Holy Roman Empire.