Arthurian legend always struck me as coming from an interesting perspective... Since Arthur would have been opposing the invading Germanics, it seemed odd to me for Arthurian legend to be such a strong thread in England, which is essentially Anglo-Saxon... i.e. all those invading Germanics Arthur was opposing. It seemed to violate the "winners own history" idea, since Arthur was obviously lauded rather than reviled.

But then I found out that much of the Arthurian legend (at least those parts that weren't retold French stories) had been maintained by the decedents of Brythonic ex-patriots who had been living in Brittany since the Anglo-Saxon invasion. Many of these people were part of William the Conquerers invading Army, and telling stories about old Arthur fighting against the evil Anglo-Saxons was good propaganda.

So, sometimes winners tell history... and sometimes winners elevate the history of old loosers when it suits them.