There had already been Norwegian and Danish settlers in the area. King Charles "the Simple" of France made an effort to chase away the Vikings, but Rolf's men triumphed at Pont-de-l'Arche, then went on to raid Melun, where the French again tried to beat them off and lost. So the Vikings ruled the area from their seat at Rouen, and mostly turned to colonization instead of pillaging. But Rolf looked beyond the Seine valley; he extended his holdings across the Risle, then the Orne, then took Bayeux in 900, killing Count Béreanger who had held it; Rolf married the count's daughter Popa. And, finally, in 911, Charles "the Simple" recognized Rolf's holdings.

http://rollo.com/geneaolgy.htm (solo con Explorer, repetir el typo)
http://www.patpnyc.com/hrolf-de.htm (solo Explorer)
http://www.mids.org/sinclair/ph/
(Hrólf) Duchy of Normandy, by King Charles "the Simple" of France, by a Treaty signed at Castle St. Clair-sur-Epte in 911 AD and from which place the Sinclairs (St. Clairs) take their name.
Child 1: Normandy, William I LONGSWORD of, Duke of Normany 2nd
Child 2: Robert of Corbeil, Count of Corbeil
Child 3: Crespina
Child 4: Gerletta
Child 5: Kathlin
Child 6: Adele of Normandy, b. ABT 917


Some say that Rollo was the same as Ganger-Hrolf, or Rollo the Ganger, who was called that because he was so gangly, to be specific, his legs were so long that when he rode a horse it looked like he was walking; Ganger means Walker. However, according to Peter Kurrild-Klitgaard, Ph.D., the early sources all distinguish the two men.