question: What made the Eastern Empire be known as the Imperium Graecorum ?
answer: Pope Leo III crowned Charlemagne , king of the Franks , as the `` Roman Emperor ''
turker_answer: Pope Leo III crowning Charlemagne , king of the Franks , as the `` Roman Emperor '' made the Eastern Empire be known as the Imperium Graecorum .
rule-based: Pope Leo III crowned Charlemagne , king of the Franks , as the `` Roman Emperor made the Eastern Empire be known as the Imperium Graecorum .