When the Vikings invade England, Alfred (David Hemmings) is about to take his priesthood vows. However, his brother, King Æthelred of Wessex (Alan Dobie), summons him to his aid and Alfred leaves for battle, where he appears to be a great tactician. Æthelred dies shortly after Alfred marries the Mercian princess Aelhswith (Prunella Ransome). Torn between following intellect or passion, Alfred at first refuses to succeed Æthelred and consummate his marriage, but is forced to accept kingship after the Danes attack again.