Charlemagne is considered one of the greatest leaders and European history because he was a brilliant warrior in general, a strong King, the Franks reached their greatest power under his rule, he also been built his Empire through extensive War. The ________ are when Lords went to war, if he called his vassals to fight with him the vassals had to come, the vassals had to give the Nobles money on special occasions if a vassal enough land he could become a lord.