A millennium before Romeo and Juliet, another doomed love - that between the Breton Tristan and the Irish princess Iseult - passed into legend. Some of the stories have the pair running off to France to live out their days; in others, they're both murdered by a jealous husband. Sometimes Tristan is a knight at King Arthur's court, other times a wandering Pict. Against a backdrop of war between the Irish and the Celtic peoples of ancient Britain, the pair fall in love and play out their respective roles in the fate of the whole of the British Isles.