A decade has passed since the death of Caradoc, King of the Dumnonii tribe, and his friend, Flavius Magnus Maximus. Britain is battered by Pict invaders, and centurion Constantinus and his legionnaires are fighting them to the death.

Maximus's daughter, Lady Severa, holds the key to the throne of the High King of the Britons and when she is threatened with abduction, Constantinus escorts her to the safety of Tintagel. Agreeing to marry her, he is crowned the High King, and Severa bears him two sons, Ambrosius and Uther. But, as the ruler of Britain, Constantinus is poisoned by greed and jealousy, and his thirst for greatness in the Roman Empire will cost him dear...