How was Charlemagne important to restoring order in Rome?

Answer 1

Charlemagne was important in many ways, restoring order to Western Europe, and many of these were reflected in Rome, as they were in the rest of the area. He reformed the currency, creating stable coinage that was used through much of the West. He united various kingdoms into a new empire, which we call the Carolingian. He was responsible for unifying the Latin language, which had already diverged into several dialects; the unified Latin was used by the Church and in courts and schools for centuries. He founded schools and raised standards of literacy. All these things had their effects on social order.

In Rome specifically, when the Roman nobility took offense at Pope Leo III because the pope was of very humble origin, Charlemagne sent troops into the city and the surrounding territory, to protect the pope and Church officers, and settled a very disturbing situation. It was shortly after this that Pope Leo III crowned Charlemagne as Emperor of the Romans.