The legions are but a memory, the glory of Rome only a shadow of crumbling ruins and broken walls.
A darkening tide of barbarism was washing across Britain's shores and the lights of civilization were slowly flickering out into darkness, only kept burning by the legendary Red Dragons cavalry unit. Led by their Tribune, Arthur, who serves no kingdom but goes where the fight is hardest and most crucial, they wage desperate battles to keep back the tide. The Red Dragons ride the length of Britannia to fight the invading Saxons, Scoti and Picts, wherever they show, from across the seas or down from the Highlands. At sixteen years old Peredur of Gwynedd has listened all his life to the stories of his father Pelinor fighting with Ambrosius Aurelianus. When word comes that his older brother has been slain in battle with the Saxons, his desire for revenge leads him to follow in his very footsteps, becoming a cavalryman with the Red Dragons. Along the way he may either find himself a warrior and leader worthy of Arthur or be left lying forgotten in the dust of history.