The year 2011 witnessed two 1,100th-anniversary celebrations relevant to the activities of Scandinavians overseas. On 2 September 911 a treaty designed to facilitate trade and promote good relations between the Byzantines and the Kievan Rus was agreed in Constantinople. The treaty between the Frankish king Charles the Simple and the viking army led by Rollo that marked the beginning of Normandy is almost virtual in comparison, in the absence of a text or a contemporary record; but, according to Dudo of Saint-Quentin, it too was granted in 911, at Saint-Clairsur-Epte. The exact nature of the power of the vikings on the Seine at that moment is obscure: their takeover coincided with a hiatus in Frankish annal-writing, and no contemporary evidence survives from church or court in Rouen. The earliest witness is an original charter in King Charles’s name from March 918 which granted the abbey of La Croix-Saint-Ouen and its dependencies to the monastery of Saint-Germain-des-Prés, praeter partem ipsius abbatiae quam annuimus Normannis Sequanensibus, uidelicet Rolloni suisque comitibus, pro tutela regni. The charter refers to the portio Nortmannorum but does not spell out its boundaries. From the 920s to the 990s Reims’s historians Flodoard and Richer occasionally reported on Norman affairs, but after what appears to have been almost a century without writing in Normandy itself, there was a surge in the reign of Richard II (996–1026) – charters, hagiography, and, of course, Dudo’s history, much of it closely associated with the dukes. These circumstances make early Normandy very difficult to reconstruct and assess. It is not a neglected subject, however: David Bates’s lucid analysis in his Normandy before 1066 remains the benchmark for subsequent discussion, and Lucien Musset’s enduring scholarship has been extended in recent years by Francophone and Anglophone historians with intimate knowledge of both local and wider Frankish contexts. Despite all this attention, there is no consensus about how things stood in the tenth century, before the change of gear that followed the accession of Richard II.

Although Rouen and Kiev offer many contrasts, it is a measure of Scandinavian vitality overseas that the same year saw two such successes. The degree to which the people involved belonged to the same world continues to be a matter for debate.