I believe that France grew significantly in power during the medieval times. I am sorry if I am wrong.
Explanation:
Charlemagne, King of the Franks and Holy Roman Emperor – The name Charlemagne comes from Karolus Magnus or Charles the Great. He became King of the Franks in 768, and for the next 46 years would build the Carolingian Empire, and become the first Emperor in Western Europe in about three centuries.
France in medieval times would be called the Kingdom of the Franks.