The Rhine and Frisian campaigns were a series of battles during the First Viking Wars. Taking place in 851 through 854, the Rhine and Frisian Campaigns occurred in and near the Rhine river. The campaigns, made possible by the powerful Byzantine navy, resulted in the destruction of most Viking ships in the Rhine river. The majority of the battles composing the Rhine and Frisian Campaigns took place between 851 and 854.
The First Viking Wars had cost the Frankish Empire dearly. The Vikings had sent a number of ships down the Rhine river to attack multiple cities and settlements. Among these cities were Cologne and Utrecht. A detachment was sent down the Meuse river, allowing the Vikings to sack Aachen, killing Lothair I. His successor, Atticus I, mobilized the Byzantine fleets and armies in order to save the Frankish Empire from the Vikings.
Atticus I retook Aachen with the Byzantine forces, saving the Frankish Empire from the marauders.
Battle of Liége
Following the Frankish/Eastern Roman victory at Aachen, the Vikings were unable to counter Atticus' forces. Attempting to draw them out of Aachen, the Vikings sacked Verdun, though Atticus did not intend on losing Aachen again. They did, however, manage to retake Maastricht. In 850, the Vikings prepared to attack Liége. Getting word of the planned assault on the Frankish city, Atticus mobilized his forces and rode for Liége, intending to prevent the Viking forces from sacking the city.
Atticus I ordered his forces to occupy either side of the Meuse River to await the arrival of the Viking ships. Upon the arrival of the Viking ships, Frankish archers opened fire, taking out many people on the Viking ships. Flaming arrows were used in the fight to cause further damage to the ships. By the time the ships had outrun the archers, the Viking numbers had been severely thinned. However, their defeat was yet to come.
The Byzantine navy had sent a few ships down the Meuse river. Eventually catching up to the Vikings, the Byzantines utilized Greek fire against the Vikings, destroying most of their forces by the time they reached Liége. The militia in the city was able to finish the stunned Vikings off, making the Battle of Liége a victory for the Franks and the Byzantines.
The Frisian area had been taken by the Vikings in order to secure territory from which to mount battles down the Rhine River. The Byzantine fleets arrived in 851, pushing the Swedish military back. The gap in the Swedish navy allowed the Byzantines to land in Viking-controlled Frisia. The Eastern Roman Empire then worked on taking the Vikings out in Frisia.
The Vikings had terrorized the Frisians during the war, making the Frisians grateful for the supposed support from the Carolingian Union. The Byzantines, however, saw the opportunity to seize land for the Carolingian Union. They turned their attention on the Frisians for a short time, however, forcing the Frisians into a quick surrender. With Frisia taken, the Byzantines were able to send ships down the Rhine river to take out the Vikings.
Battles in the Rhine
With the Frisians under Carolingian control, the Byzantines fought the Swedes and Danes in the seas north and east of the Frisian area. During this period, the Byzantines and Vikings engaged in a number of naval battles. While the Byzantines had Greek fire, the Vikings also had a similar fire-starting liquid that was highly effective against wooden targets. The legendary naval battles are said to have been the most impressive in history at the time, with fire and sails dominating the ocean horizon for miles at times.
The year 852 was marked by multiple naval battles along the Rhine River. With the Byzantines attacking the Swedes and Danes, a number of Byzantine ships were sent down the Rhine river in order to flush out the Vikings. By 853, the Vikings had been largely expelled from the Rhine river. The last Viking ship in the Rhine was destroyed in mid-854, ending the Rhine and Frisian Campaigns.
The Rhine and Frisian Campaigns allowed for the Franks to somewhat recover from the Rhine Raids. With the Vikings out of the Rhine area, the Franks were able to divert their full attention to the invading forces near Jutland. Before long, the Frankish Empire expelled the Danes from Frankish territory at the Battle of Hammaburg Castle in 853.