Fantastic composition. What a beautiful place to die in.
The Saxons were still a hard piece to chew and swallow for the Carolingian Empire. Thirty years of war, rebellions and repression, approximately from 772 to 804 AD, to submit the last true germanic people.
And he had the pretension of being the first Emperor of a reborn Western "Roman" Empire.
Sure, he poisoned his own brother Carloman to reunite the divided frankish kingdom. He conquered the Kingdom of Lombardy in northern Italy and thus saved Rome from the Lombard whose king had Carloman's children in his guard. He destroyed the Avar Khagnate of Pannonia after a series of genocidal military campaigns. And, last but not least, he succeeded where the Romans had failed : submitting the wild Germania, kind of ironic since the Franks themselves were of germanic descent like the Saxons.
By all theses success, the Frankish Kingdom extended to the size of a considerable Empire and became THE game master in the Western Europe. You gotta give Charlemagne the credit of being the father of a unified Europe.
But Charlemagne never succeeded to conquer the old provinces of Hispania, protected by the Pyrenean Chain, divided between the Umayyad Caliphate of Al-Andalus to the south, the rebellious Taifas and the visigothic-vascian kingdoms like the Asturias to the north.
Neither did he tried to reconquer Africa (held by the Abbassid Caliphate with whom Charlemagne was allied against the Umayyad), nor Britannia (he corresponded with the main anglo-saxon king Offa of Mercia).
When the carolingian dynasty split up into different kingdoms, there are clear indications of the areas/borders of germany and france.
The Carolingians pretty much set up the foundations of Western Europe.