Final answer:
Charlemagne was an influential ruler who united western Europe and set the stage for conflict between east and west. Pope Gregory the Great played a significant role in expanding the influence of the Church and spreading Christianity in western Europe.
Step-by-step explanation:
Charlemagne::
Charlemagne, also known as Charles the Great, was an influential ruler in medieval Europe. He conquered land, subjugated people, and extended his empire across central Europe, uniting western Europe for the first time since the collapse of Roman authority. Charlemagne's coronation as Emperor of the Romans by Pope Leo III set the stage for conflict between east and west and enabled cooperation and conflict between popes and emperors.
Pope Gregory the Great::
Pope Gregory the Great was an early pope who played a significant role in the development of medieval Europe. He shrewdly used his spiritual authority to gain the trust and support of different Germanic kings, helping to expand the influence of the Church. Gregory sent missionaries to spread Christianity, contributing to the wider influence of the Church and the growth of cultural and religious cohesion in western Europe.