At the outset of the Viking Age, the Frankish Empire was the most powerful political force in Western Europe. It was ruled by Charlemagne, the first Holy Roman Emperor. The alternative name ‘Carolingian Empire’ is often used to describe the territory ruled by Charlemagne and his descendants, after the Latin form of Charlemagne’s name, Carolus Magnus (Charles the Great in English). Under Charlemagne, the Frankish kingdom had rapidly expanded until it stretched from Saxony to northern Italy. In recognition of this dominion, Charlemagne was crowned as Holy Roman Emperor in 800. Yet the power of this empire did not prevent Viking raids along the Frankish coast, as well as in Britain in Ireland. In fact, the Carolingian expansion may have been one of the reasons why the Viking raids began in the first place. The Danes were perched on the doorstep of this vast empire which they had no hope of resisting militarily. However, with small military forces in fast ships, Vikings could target undefended coastal sites before the imperial machine was able to drum up the forces to oppose them. The fact that the Franks were able to exert a monopoly on legitimate trade simply gave the Vikings added incentive to pursue this option. Furthermore, the power of the Carolingian Empire may have caused a knock-on effect: the Danes were forced to build up their own power within Scandinavia and exert their own control of trade. This led Norwegian chieftains to look for raiding and trading opportunities over the sea to the west, in the British Isles and Ireland.
In order to secure the withdrawal of the Viking army, Charles the Bald made a payment of 7000 livres (approximately 2,570kg of silver and gold). This was not the first attack on Paris; several raids took place in the 860s. The biggest attack, however, came in 885–886, when a Viking fleet numbering as many as 700 ships sailed up the Seine and besieged the city (although they were unable to penetrate the defences) until they were persuaded to withdraw with the offer of yet more tribute. The raid led to a decline in relations between the Frankish emperor, Charles the Fat, and his noble subjects (particularly Count Odo of Paris) as Charles refused to attack the Viking army outright, instead allowing them free reign to raid Burgundy, which was in revolt. Odo was instrumental in having Charles deposed in 887 to die early in 888. The Carolingian Empire was permanently divided, with Odo becoming king of the West Franks: once again, the Vikings had played a key role in political events, in this case contributing to the fall of the largest European empire since the Roman period. The Norse would continue to play a political role in Francia in the following century, but increasingly as permanent residents: the Normans.