What countries did Charlemagne conquer?

Charlemagne, the King of the Franks and later Emperor of the Carolingian Empire, expanded his territory through numerous military campaigns. He conquered much of modern-day France, Germany, the Low Countries (Belgium and the Netherlands), Switzerland, Austria, and parts of Italy, including northern Italy and Rome. He also conducted campaigns against the Saxons, Avars, and Lombards, significantly shaping the political landscape of medieval Europe. His conquests laid the foundation for the future Holy Roman Empire.