The mighty king of all primeval England, Uther Pendragon, lusts after Igrayne, wife of the Duke of Cornwall. Uther invites the duke and his wife to his castle and propositions her. She refuses him, tells her husband, and the duke and Igrayne slip out of Uther's castle by night and flee. On the advice of his knights, the king, sick with lust and rage, marches on the Duke of Cornwall. While the siege is still on, Merlin the magician arranges a pact with King Uther. He will transform Uther into the image of the duke and get him to bed with lgrayne. The condition is that the child who will be conceived on this night shall go to Merlin for rearing as he sees fit.
The child is conceived hours after the real duke's death, and King Uther later marries the widow. On the same morning, by King Uther's request, two fellow kings — Lot and Nantres — marry two of Uther's daughters, and the third daughter, Morgan le Fay, is put to school in a nunnery and becomes a necromancer; she later marries King Uriens. The child is born and delivered unchristened to Merlin.
Two years pass. In this time Uther's enemies strike at him repeatedly, killing many of his people. Uther falls sick, and in the hour of his death, Merlin gets him to proclaim his son Arthur the future king of England.
After Uther's death, the kingdom is in jeopardy, every baron struggling to seize control. Merlin goes to the Archbishop of Canterbury, tells him a miracle is coming soon and advises him to assemble all the lords of the kingdom at Christmas. They come and find a sword lodged in a stone, and on it the legend: Whoso pulleth out this sword from this stone and anvil is duly born King of all England. No man can budge it, and to keep them in hand, the archbishop arranges a New Year's Day tournament. To this tournament a knight of low station, Sir Ector, comes with his son Kay and the child Merlin placed in his care, Arthur.
