Vikings in France, Iberia, and the East: Normandy, al-Andalus, and Kievan Rus

Viking pressure on the West Frankish kingdom intensified from the mid-ninth century, with the Seine becoming a standard invasion route; a Viking force sacked Paris in 845 and extracted ransom from King Charles the Bald, and a great siege of Paris in 885-886 was repelled by Count Odo. Into this world stepped Rollo, a Viking leader who, through the Treaty of Saint-Clair-sur-Epte (911), received from King Charles the Simple the territory that became the Duchy of Normandy in exchange for his fealty and conversion to Christianity. Rollo's descendants assimilated rapidly into Frankish culture, and their duchy became one of the most dynamic feudal powers of medieval France; in 1066 the Norman duke William the Conqueror crossed the Channel, defeated Harold Godwinson at the Battle of Hastings, and became king of England — days after Harold had already destroyed a Norwegian invasion under Harald Hardrada at the Battle of Stamford Bridge, an event conventionally regarded as marking the end of the Viking Age.