In this history there were three-and-a-half main invasions that were clearly moralised in terms of the peoples: the Roman invasion of the Ancient Britons (we did not talk much of 'Celts' at that time); the Anglo-Saxon and Jutes invasion of the Ancient Britons; the Viking/ Dane's half-invasion of the Anglo-Saxons; and the Normans invasion of the Anglo-Saxons.
Among these the 'goodies' were the Ancient Britons both times; and then the Anglo Saxons. The interesting thing is that 'we' were first the Ancient Britons and then, after they had been defeated, 'we' became the Anglo-Saxons.
But this is not modern - the same shift can be seen in the earliest chroniclers of British History from the Saxon times up through into the medieval era - the general stance is that the goodies were the Britons/ Celts and the baddies were the invading Anglo-Saxons, even when written from the Saxon victors (or Nomran occupiers) perspective. The whole Arthurian and Merlin legend, always popular, is based on this implicit assumption.
I think the key to this is that sometimes the moral good is derived from patriotism - so that the resident English (i.e the Ancient Britons get the moral approval when against Romans - despite druidic human sacrifices and the benefits of Roman Civilisation'); but that this aspect is trumped by religion.
Religion trumps patriotism.
So that when there is a Christian versus a Heathen conflict, then the Christian side will always be the goodies. This is why the Ancient Britons were the goodies in the post-Roman conflicts until the Anglo-Saxons became Christian; and why the Christian Anglo-Saxons were goodies against the pagan Vikings (despite that people such as myself - i.e. the blue-eyed - almost certainly descend from the Scandinavians, because that was where the blue-eyed mutation occurred).
When it comes to the final invasion of 1066 - and the Anglo-Saxons versus Norman conflict - we have Christians versus Christians for the first time in our island history.
Therefore, the Saxons are strongly felt to be the goodies, and 'we' are the armies of Harold, defending against the alien William the aggressor and usurper - because when both sides are Christian, 'we' defaults to the resident Anglo-Saxon English, i.e. on patriotic grounds.
