If I ever remotely thought about it, I suppose I imagined the Normans were of a genetically Frankish/Gaulish origin, "Norman" due to their "northern" location on the French map. Wrong.
North Men, it turns out, were from a place real north, not a French 'burb. They were Vikings who stayed and married the local, rich girls. From Wiki; "The Viking contingents who raided, and ultimately settled Normandy and some parts of the Atlantic coast, included Danes, Hiberno-Norse, Orkney Vikings, as well as Anglo-Danes from the English Danelaw, under Viking control." And William the Conqueror was a grandson of Rollo, who successfully besieged Paris with Sigfred. Rollo's Wiki article has this cultural gem, "Legend has it that an emissary was sent by the king to find the chieftain and negotiate terms. When he asked for this information, the Vikings replied that they were all chieftains in their own right." According to the articles, the raiders learned French quickly, but it appears they never fully embraced the continental lifestyle, not if this passage is an indication,
Specially marked by cunning, despising their own inheritance in the hope of winning a greater, eager after both gain and dominion, given to imitation of all kinds, holding a certain mean between lavishness and greediness, that is, perhaps uniting, as they certainly did, these two seemingly opposite qualities. Their chief men were specially lavish through their desire of good report. They were, moreover, a race skillful in flattery, given to the study of eloquence, so that the very boys were orators, a race altogether unbridled unless held firmly down by the yoke of justice. They were enduring of toil, hunger, and cold whenever fortune laid it on them, given to hunting and hawking, delighting in the pleasure of horses, and of all the weapons and garb of war."
It's good to know the truth, actually, because Norman conquests were the exception to that old saying, "Well, at least we can always defeat the French." Rather, Normans further proved the point.