Geoffrey of Malaterra - Book I
The land of Normandy is in Gaul, but it was not always called Normandy. Once it, and everything that appertained to it, was a part of the royal fisc of the King of the Franks, which was called by the general name of Francia; up to the time when a very brave leader called Rollo sailed boldly from Norway with his fleet to the Christian coast, accompanied by a strong force of soldiers. He ravaged Frisia and other maritime areas to the west, and finally reached the port where the River Seine flows into the sea. His great fleet sailed up this river into the more inland areas of Francia, and seeing how fertile this area was, more so than the other regions which they had crossed, he conceived a desire to seize it and take it for his own. For it is a land with rivers full of fish and woods full of wild animals, fertile and suitable for corn and other crops, with rich meadows to feed cattle, and thus very likely to excite the greedy. For this reason they landed on each bank and began to make the inhabitants of the province subject to his rule.
However, the king who was at that time ruling over Francia, I think it was Louis II was at first furious when he learnt that enemies had invaded the frontiers of his empire. He raised an army, marched against the enemy and appointed a duke to expel them from his lands. But then he realised that this could not be done without great casualties among his men. Fearing the uncertain events of war and wishing to spare bloodshed among his followers, he took counsel and concluded a peace treaty.
Accepting the service which they offered to him, he granted them the bulk of the land which they had invaded as a benefice.
The land which had been granted to them stretched [westwards] from thepagus of Ponthieu on its eastern border, and was next to the English Channel, which lay between it and Britain on its northern side and bounded its western extent also. On its south west frontier there was the pagus of Maine, and then the border went as far as Chartres, from Chartres it went to Abbeville and Beauvais, up to Ponthieu [once again].
Duke Rollo received this land outlined above from the King of the Franks as a hereditary fief; he then distributed it among his followers depending on how close he was to them, reserving the most valuable land for his own use.
There was a certain knight of quite distinguished family who possessed this village [Hauteville] by hereditary right from his ancestors. He was called Tancred, and he married a wife called Moriella, who was notable both for her birth and her good character, and as the years went by he received from her in lawful manner five sons, who were in the future to become counts: namely William, known as 'the Iron Arm', Drogo, Humphrey, Geoffrey and Serlo.
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John Bagnell Bury - The Cambridge Medieval History - Vol.V (1926)
The establishment of the Normans at Aversa was followed by a considerable influx of their compatriots, a tendency always warmly encouraged by Rainulf. The new arrivals were cordially received at his court, and very soon Aversa became the centre where all adventurers coming from Normandy could forgather; it was a kind of market where those in need of soldiers could engage them.
Among the adventurers who came thither between 1034 and 1087 were the sons of a petty Norman noble, Tancred de Hauteville, whose name was to receive enduring renown from the exploits of his descendants. Tancred, who held a fief of ten men-at-arms at Hauteville-la-Guicharde near Coutances, was not rich enough to bestow an inheritance on all his numerous children.
By his first wife, Muriella, he had five sons, William, Drogo, Humphrey, Geoffrey, and Sarlo; by his second, Fressenda, he had Robert Guiscard, Manger, William, Auvrai, Tancred, Humbert, and Roger, to say nothing of daughters.
The two eldest sons, William and Drogo, realising the modest future which awaited them if they remained under the paternal roof, resolved to seek their fortunes abroad, and started for Aversa.
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William Iron Arm of Hauteville was the first Count of Apulia;
Robert Guiscard of Hauteville was the first Duke of Apulia and his brother Roger Bosso of Hauteville was the first count of Sicily;
Roger II of Hauteville was the first King of Sicily;
There is a legend that Tancred was descendant of Ogier the Dane;