"Macduff"

The historical equivalent of the character represented by Shakespeare in That Scottish Play. Other than his spanning the reigns of Malcolm II, Duncan I, Macbeth, and Malcolm III [what evidence that he does? Sharon Dec 2015], probably very little in the play is accurate.

Existence attested only by a charter universally declared to be spurious (though some think it may have been "creatively reconstructed" circa the short reign of Malcolm IV).

First (surviving) appearance in print: John of Fordun, "Chronicle of the Scottish Nation", c. 1360. https://archive.org/stream/johnoffordunschr00fordrich#page/180/mode... https://en.wikipedia.org/wiki/John_of_Fordun

Second known appearance: Andrew of Wyntoun's "Orygynale Cronykil", c. 1413-1420 (abbreviated prose version here: http://www.electricscotland.com/webclans/m/macduff2.html)

Neither version includes the heinous murder of Lady Macduff and her children - this was apparently a later evolution.

Scholarly opinion is divided as to whether Wyntoun worked off a copy of Fordun, or if they were both independently working off a lost Ur-source.