In "Europe's Long Twelfth Century" John D. Cotts says that after the Norman Conquest the Anglo-Saxon nobility was "essentially eliminated." (p. 50) Due to short length of the book he doesn't elaborate on this point. Were the all killed in the battle of Hastings? Was there a massacre of the remaining nobility after William became king?
This is the first time that I feel sort of qualified to answer a post on AskHistorians so I will take this with both arms. Last year I wrote an essay about William's approach to the Anglo-Saxon nobility.
When William conquered England he had the full intention to cooperate with the Anglo-Saxon nobility. Of course a portion of them had died during the invasion(s) and another portion had fled England to seek better lives elsewhere but he allowed Anglo-Saxon and Norman nobles to marry each other and even gave them land. Even though he tried to be a benevolent ruler he quickly encountered a lot of resistance from the Anglo-Saxons who could just not be pleased with their new overlord. A lot of this resistance was fueled by family members of the previous English monarchs. After these uprisings William often chose a rather pragmatic course of action, take their land away and get rid of them. So during his early years the number of Anglo-Saxon landholding nobles was already slowly diminishing because they kept revolting against the Norman rule.
The continued uprisings changed William's approach, a famous example of this is the Harrying of the North. A ruthless campaign where William's Normans simply destroyed the North and subsequently William replaced the Anglo-Saxon nobles there. William turned England into his private property almost and redivided all lands, signalling an end to the landed Anglo-Saxon nobility. A few outlasted William but his successors took care of that.
So in essence the Anglo-Saxon landed nobility in England disappeared due to constant uprisings, they assumed the Norman rule over England was weak but the Norman tactic of simply erecting motte and baileys on vital strongpoints and holding out there against the Anglo-Saxons worked. In the end the Anglo-Saxon nobility kind of dug their own grave by constantly trying to get rid of the Normans, changing the Norman policy and ending their careers as landholders in England.
Sources: Bates (William the Conqueror), Clanchy (England and its Rulers), Loyn (Anglo-Saxon England and the Norman Conquest), Huscroft (The Norman Conquest).
Those books are all good reads but if you want to learn more about William and the conquest I would recommend Bates. Broad but still enough detail.
In what ways, if any, were the romans spoken about, or mentioned in this history? (I understand this is hundreds of years after they abandoned the island).