Could an ambitious Anglo-Saxon lord invade and conquer France? If possible, what would the effects be on french culture and society?
Maybe we could do it by changing the Frankish national character? Make them more egalitarian, have kingship be a social contract, etc. This could cause a succession crisis when a dynasty falls out of power, much like the one when the House of Wessex fell out of power in England.
I mean, the Frankish crown was elective for centuries, into the 11th IIRC.So, maybe the Frankish crown is decided by election? Perhaps some Anglo-Saxon or Danish lordling is able manipulate the election and have themselves declared King?
This is sort of how Normandy was founded in the first place. Just have Anglo-Saxon raiders instead of Danish vikings conquer the northern coast of France.