In Nennius’s description of the battle of the Castle Guinnion, Arthur is said to have
carried an image of St. Mary, the Perpetual Virgin on his shoulders.
The Annales Cambriae similarly describe the “Battle of Badon, in which Arthur carried the cross of Our Lord Jesus Christ for three days and three nights on his shoulders”. Both of these passages, particularly the second, invoke an interesting and somewhat absurd image. It is likely, however, that the sources of both authors intended for Arthur to bear the insignia on his shield, with the Welsh word for “shield” (yscuit) mistranslated as “shoulder” (yscuid). Geoffrey of Monmouth, consequently, transfers the image of the Virgin Mary back to his shield.
In Medieval times, the church of St. Mary of Wedale in Selkirkshire claimed to have a fragment of this emblem; however, it is unlikely that either of these allusions are authentic, since emblems or devices on shields are unknown this early in history.