Charlemagne was known as”the father of europe”. how does this map to explain that title

I believe the answer is It shows that Charlemagne conquered a huge part of Europe.
Charlemagne became the first man in history to conquer Western Europe since the downfall of the Roman Empire. Eventhough his empire was not as large as the Romans,  His achievement still pretty much respected becuase many experts believe that the current France and England is the fragments of what used to be Charlemagne's empire.