The Principality of Normandy
In the Treaty of Saint-Clair-sur-Epte (911) with King Charles, Rollo pledged feudal allegiance to the king, changed his name to the Frankish version, and converted to Christianity, probably with the baptismal name Robert. In return, King Charles granted Rollo land between the Epte and the sea as well as Brittany and according to Dudo of St. Quentin, the hand of the King's daughter, Gisela, although this marriage and Gisela herself are unknown to Frankish sources. He was also the titular ruler of Normandy, centered around the city of Rouen. There exists some argument among historians as to whether Rollo was a "duke" (dux) or whether his position was equivalent to that of a "count" under Charlemagne.
According to legend, when required to kiss the foot of King Charles, as a condition of the treaty, he refused to perform so great a humiliation, and when Charles extended his foot to Rollo, Rollo ordered one of his warriors to do so in his place. His warrior then lifted Charles' foot up to his mouth causing the king to fall to the ground.
After 911, Rollo stayed true to his word of defending the shores of the Seine river in accordance to the Treaty of Saint-Clair-sur-Epte, however he also continued to act like a Viking chief with attacks on Flanders.
After Charles was deposed by Robert I, Rollo considered his oath to the King of France to be over. It started a period of expansion westwards. Negotiations with French barons ended with Rollo being given Le Mans and Bayeux and continued with the seizure of Bessin in 924. The following year saw the Normans attack Picardy.
Rollo began to divide the land between the Epte and Risle rivers among his chieftains and settled there with a de facto capital in Rouen. Eventually Rollo's men intermarried with the local women, and became more settled as Normans.
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