Charlemagne's capital was Aachen, which is also known as Aix-la-Chapelle.
Charlemagne was not crowned emperor of a city. He was crowned Emperor of the Romans, implying that he was ruler of the Roman Empire. There was, and still is, much controversy over this event. We do...
Aix-la-Chapelle
Charlemagne was crowned emperor in Rome.
Aix la Chapelle