|The making of the Duchy of Normandy|
Rollo, leader of the Vikings of the Seine
Having been exiled from Norway, Rollo would have begun his career as a mercenary in the service of an English king, employed to fight the Danes who occupied the north of the island. He subsequently operated as a Viking on his own account, and set himself up in 876 at the mouth of the Seine. In 886 he associated himself with the fleet that had been besieging Paris for some time and took advantage of this arrangement to further his own ends in Normandy by seizing Bayeux and Evreux.
From this period onward, the Vikings established in the lower reaches of the Seine seemed to have set themselves the objective of extending their territory to the west. Saint-Lô was taken in 890 after a long siege, but the Norman expedition was almost immediately beaten by a coalition of the Breton chiefs. Furthermore, Rollo probably had no authority over all the Scandinavian groups installed in the region, but from the end of the 10th century he became the indispensable ambassador for the Marquis of Neustria. He would have also retained a relationship with Alfred the Great, King of Wessex, who he would have continued to help against the Danish kingdom of York.
Rollo was still a man with a foot in two worlds. A leader recognised by the powerful of his time, on the eve of accession to a territorial princedom, he continued to associate himself with seasonal pillaging expeditions which were the stock in trade of the Vikings. It is also the case that he did not always come out on top. In 911, he suffered a major defeat in Chartres. His position remained strong enough, however, for him to be involved in negotiating the accord which was to give rise to the creation of Normandy.