The following excerpt is from The Life of King Edward who rests at Westminster. Attributed to a monk of Saint-Bertin. 2nd ed. Ed. and Trans. Frank Barlow. Oxford: Clarendon Press, 1992. Notice how the writer referred to Macbeth as “the king of the Scots with an outlandish name” (rex Scottorum nomine barbarus). The narrative makes it seem like it is Macbeth who fought with, and later surrended to, Tostig Godwineson, when it is in fact King Malcolm who did so.
p. 66: Insurrexerunt enim uno ferme tempore hinc rex occidentalium Britonum Griphinus, illinc rex Scottorum nomine barbarus.
Alter vero primum a Siwardo duce usque ad internitionem pene suorum deuictus, et in obscenam fugam est versus, secundo ducatum agent educe Tostino cum eum Scotti intemptatum haberent, et ob hot in minori pretio habitum, latrocinio potius quam bello sepius lacesserent; incertum genus hominum et leue, siluisque potius quam campo, fuga quoque magis fidens quam audacia virili in prelio, tam prudenti astutia quam virtute bellica et hostile expeditione cum salute suorum predictus dux attrivit, ut cum rege eorum delegerint ei regique Aedwardo magis seruire quam rebelare, id quoque per datos obsides ratum | facere.
p. 67: There rose, for example, almost at the same time, on this side Gruffydd, king of the West Britons, and on the other the king of the Scots with an outlandish name. The former, however, with Earl Harold directing the English army, was often defeated, and in the end killed. But we deliberately reserve this story for a more faithful treatment in the future. It is rather protracted and complicated, and can be explained better in a longer report. Besides, the man whom we, impressed by the burden of the labour he undertook and his unusual industry, have undertaken to describe in this book (but not without uneasiness of mind)[…]. The Scottish king, too, was first defeated with the destruction of almost all his men by Earl Siward and forced to take shameful flight. Then, when earl Tostig ruled the earldom, the Scots, since they had not yet tested him and consequently held him more cheaply, harassed him often with raids rather than war. But this irresolute and fickle race of men, better in woods than on the plain, and trusting more to flight than to manly boldness in battle, Tostig, sparing his own men, wore down as much by cunning schemes as by martial courage and military campaigns. And as a result they and their king preferred to serve him and King Edward than to continue fighting, and, moreover, to confirm the peace by giving hostages.