Nennius records that here "Arthur bore the image of the Holy Virgin, Mother of God, upon his shoulders, and through the power of our Lord Jesus Christ, and the Holy Mary, put the Saxons to flight, and pursued them the whole day with great slaughter."
Gurnion Castle is another battle site that remains unknown
It has been remarked that it is strange for Arthur to be carrying the image on his shoulder instead of on his shield (which is far more likely). This shows the problems of translation - Scuid in old Welsh means shoulder, while scuit in Latin means shield. Nobody really knows which is correct.
The Battles of King Arthur