So. I am listening to a performance of the Highland ballad The Bonnie House of Airlie, which is sad and moving in a George R. R. Martin sort of way. There is sex and violence and bloodshed. The bit of historical grit in the pearl of the drama was a conflict in the 1640s when Archibald Campbell, Earl of Argyll, raided Airlie Castle, the home of James Ogilvy, Earl of Airlie.
But the earliest version preserved was a printed broadsheet from 1790, and Child collected oral versions in the 1870s.
And the surviving versions transmute the historical Ogilvy support of Charles I to support for "Charlie" who is "awa'", referring not to Charles I of England but the young pretender Charles Edward Stuart a century later.
The oral tradition is slippery and undependable. If the Song of Roland can't even get the enemy right....