Answer:
How does the size of this area compare with the extent of the kingdom of the Franks in 768?
The kingdom of the Franks in 768 included what is now France (except for Britanny), the Low-Countries, South-Central Germany, and what is now Switzerland.
Charlemange added Eastern Germanic territories, Northern Italy and Central Italy, and the Hispanic March.
What parts of present-day Italy did Charlemagne conquer?
He conquered Northern and Central Italy, from the Alpine Regions to Rome.
How might this affect the pope?
Rome became part of the Carolingian Empire, which subjugated the pope the Charlemagne's power. However, he and Charlemange struck a deal: the pope crowned Charlemagne as Holy Roman Empire, and Charlemagne gave the pope direct control over a few areas in central Italy: in what became the Papal States.
