Francish Carolingian Coin Depicting Charlemagne

After the fall of the Western Roman empire, Rome retreated from lands as her generals were defeated. The Merovingian dynasty rose in the 5th century with the defeat of Syagrius, the last Roman general of Gaul and lasted until a family of advisors slowly took control of running the country, transitioning to the Carolingian Empire, of which Charlemagne, the Holy Roman Emperor, as he was crowned, was the most famous. He conquered and grew the empire. Medieval Christians still held the last vestiges of the Roman empire, the Eastern Byzantine empire, as a dominant force in Christendom. Then Constantine VI was deposed and replaced by his mother Irene. For a number of reasons (included in them that she was a woman), the Pope at the time, Leo III, named Charlemagne as the emperor of the Romans rather than naming Irene Empress. She could rule the Byzantine lands, but Charlemagne could now legitimately conquer to his delight.

Charlemagne had became king of the Franks in 768 and continued the overhaul of the financial systems begun by his father Pippin the Younger. They made the right to mint coins a royal privilege and established the Carolingian pound, a standard weight and measurement. Each pound of silver would be split into 240 denarii, now denier. That practice spread to England, who hadn’t minted coins after the Romans withdrew, as the pfenning and then schilling, and to Vienna and the Dutch as the Mark. These were all within a gram of one another. The denier evolved and the denier parisis was minted until the fourteenth century and the denier sou, and livre parisis were made until the seventeenth century in France.

Charlemagne knew the empire had outgrown what one person could rule with the technology to communicate at the borders of the era, just as the Roman empire had collapsed under such vast lands. His empire was split into three, which his son passed to his grandsons. And so the Carolingian empire had made the Eastern Slavs into tributaries of the Franks. There were hostilities but by the Treaty of Mersen in 870 the split of the empire generally looked like the borders of northern Italy, France, and Germany - although Germany also included Austria but not yet Bohemia. It split and re-merged and smaller boundary changes happened but that left the Slavs and Vikings aware of these larger empires and norms, like coins, flowed between them.

The borders Charlemagne pushed to in the east never touched the Byzantine lands, and so there was never open conflict between what the Roman Byzantines might have considered barbaric Franks and Constantinople. Still, as the Byzantine empire contracted, alliances of sorts were drawn. The Russian empire claimed to carry on as the third Holy Roman Empire, much as the states in Europe did. Constantinople was alone. Charlemagne, the growing Russian empire, the rising caliphates, and the Byzantines continued to try to influence and sometimes extort the lands between them, and there are plenty of examples of communications between these empires, one of the most important being the coins that flowed between them - often found in archaeological digs in far away lands from where they were minted (or stamped).