william the conqueror and his successors did what
When William I invaded England it was already an 'old and settled country' (Sir Frank Stenton). It had a very strong central government already and central governments are easy to take control of. [ William really didn't have to do a great deal, records were kept in the exchequer of what was owed to the king by whom, and with the continental feudal system replacing the Anglo Saxon government it
was an almost seamless take over, at least for the ordinary man in the street.
William replaced one form of centralised government with another. All that had to be done was to continue doing what both sides had been doing for generations. The only particular action taken by any ruler to cement this was the compilation of Domesday Book, which could not have been done had the Anglo Saxon model of government not been as sophisticated as it had been - the first set of information, 'who held the land in the time of King Harold?' could not have been answered had such information not been to hand for the circuit judges who complied the survey......
There are no new answers.