In the wake of the collapse of the Roman Empire, many people sought to pick up the mantle of this once world-spanning state. One of the most powerful Roman pretenders were the Franks, who quickly conquered the many squabbling barbarian tribes of the Western Roman Empire. The greatest Frankish King was Charles the Great, or Charlemagne.
He expanded the already impressive Frankish Kingdom past the Pyrenees, the Alps and the Elm. It didn't take long until his domain had effectively filled up the power vacuum left by the Western Roman Empire. Where the Byzantines were distracted by their own conflicts, he quickly gained favour with the Papal States of Italy by protecting them against the Kingdom of the Lombards. This eventually wrangled the Pope and large parts of Italy from the grasp of the Byzantine Emperor. Influencing the Pope to crown Charlemagne Emperor of all Romans and Franks, much to the dismay of the Eastern Emperor.
Of course. There had been massive floodings since then. You would need special maps that have reconstructed the course of the coast in historical time. In Germany there is the "Putzger" Historischer Atlas standard for such themes.
It was Charlemagne's personality and the fact that of the intended heirs to a future DIVIDED empire (the promogeniture pracrtice had not been established yet), only LOUIS I lived when Charlemagne died (814) that the Empire of the West lasted as long as it did.
Also the Empress of the East bid to marry the Emperor of the West so as to recreate the Roman Empire. BUT this plan fell through. France (west section), Germany (east section) and Lotharingia (middle, now broken up into sundry & divers areas) and finally numerous duchies & counties that were bonded by fealty to the king.
Strangely enough, Lothair the 1st inherited the title of Emperor after Charlemagne died, however only owned the Middle Frankish Kingdom by the name of Lotharingia. After Lothair the 1st died the title of Emperor passed to Louis the 2nd of Italy. Louis only had one child, a daughter. So the title for the Frankish Empire went to Charles the Bald of France.
After Charles died, the title of Emperor seemed to have lost its meaning as his heir (Louis the Stammerer) refused the title of Emperor, and died with 2 heirs who ruled West Francia together.
Eventually Charles the Fat received the title of Emperor from the Pope. Whether or not this could be legitimate crowning as King of the Franks (as it isnt hereditary) could be argued. However he had essentially united the land that had been in the "Kingdom of the Franks" his death in figuring out who is the King is important as he did not have any legitimate children. So when he died the Empire was split apart never to be united again.
Whether or not the title of "King of the Franks" even meant anything towards the end of Charles the Fat's reign could also be argued, but after his death the title did not continue anywhere. According to Wikipedia (very reputable I know) the final attempt at reuniting the Frankish Empire was during the Anglo-French War from 1213 - 1214 where the Holy Roman Empire was defeated at the Battle of Bouvines.
Long story short, neither of them are closer unless you are thinking strictly land wise, which did not define the Frankish Empire.
If I am wrong, I would love for someone to correct me as that means I also have the opportunity to learn.