The legendary king of the Franks known for unifying large parts of western Europe during the early Middle Ages was Charlemagne. Ascending the throne in 768 AD, he expanded his empire through military conquests and strategic alliances, laying the groundwork for what would later become modern-day France and parts of Germany and Italy. In 800 AD, he was crowned Emperor of the Romans by the Pope, signifying his influence and authority in both political and religious spheres. Charlemagne's reign led to a revival of learning and culture, often referred to as the Carolingian Renaissance, and he is regarded as a pivotal figure in European history.