(This summary is based upon the copy of Sir Gowther found in National Library of Scotland MS Advocates 19.3.1.)
The Duke of Austria is childless and threatens his wife with divorce if she does not quickly conceive. She is in an orchard one morning when a person she believes to be her husband arrives and they make love beneath the trees. However, she has been the victim of the utmost deception. She has been deceived in much the same way that the Duchess of Tintagel is deceived when King Uther Pendragon, cast into the likeness of her husband by Merlin, fathers King Arthur upon her in the Vulgate Merlin.[10] Like the wife of Sir Orfeo, she is accosted by a fay in an orchard. The anonymous author of Sir Gowther has already told us: "I searched high and low for a Breton lay and have brought out of this marvellous region the following tale:
- A law of Breyten long y soghht,
- And owt ther of a tale ybroghht,
- That lufly is to tell."[11]
The child the lady now carries in her womb is Merlin's half-brother, we are told. But he is a fiendish child. As a baby, he sends numerous wet-nurses to their graves and tears off his mother's nipple on the only occasion she dares to suckle him. As he grows to be a youth, hunting becomes his favourite pastime, but as he nears adulthood he prefers to roam the land with a huge sword, terrorising everybody and in particular, the religious orders. He rapes with relish and then burns a convent of nuns to death. His father is so sickened by his son's behaviour that he dies of shame.
Sir Gowther is now duke after the death of his father. But when he has his fiendish parentage thrown at him in accusation one day, he runs to his mother to find out if it is true. At the point of his sword, she admits to everything and, in a sudden change of heart, Sir Gowther resolves to travel to Rome to receive absolution for his sins from the Pope.
Sir Gowther receives an audience with the Pope and is given the penance that he may not speak and that whatever he swallows must first have been in the mouth of a dog. The curious, possible implications of this are almost corroborated when, having been kept alive for a few days by a greyhound, he dashes into the palace of the Emperor of Germany (the Holy Roman Empire), hides beneath a table and the emperor's steward comes towards him brandishing a stick. However, he is soon adopted by the court as Hob their fool and eats beneath the tables with the dogs in the evening.
The Emperor of Germany has a daughter who is mute, but this does not stop a sultan coming to claim her hand in marriage. The emperor refuses and a dreadful war begins. On three successive days, Sir Gowther, as Hob the fool, prays to God that he might be given arms to help defend the emperor's lands from the heathen hoards. And three times, he is rewarded by the magical appearance of a horse and armour outside his small room. For three days in succession, he sallies out with the emperor's army and fights invincibly, first as a black knight, then as a red knight and finally, on the third day, as a white knight, even managing to cut off the sultan's head during the final day's fighting. Like the Anglo-Norman romance hero Ipomedon, he fights in differently-coloured arms every day and nobody knows who these knights are who have conducted themselves so magnificently on the field of combat. The emperor's daughter, however, knows the truth. However, she is mute and thus unable to tell anyone anything.
But victory comes at a price. Following the sultan's death, on seeing Sir Gowther wounded on the final day of battle, the emperor's daughter, in her anguish, falls from her tower. The Pope is summoned to bury her. But as the funeral is about to start, she awakens from her bier and tells the assembled gathering that God has forgiven Sir Gowther all his sins. He may speak again, and so can she.
Following this miracle, the two are married and, when her father dies, Sir Gowther becomes Emperor of the Holy Roman Empire. He builds an abbey and attaches to it a convent, in which nuns can pray for the souls of the poor nuns he once burnt alive in their church. When Sir Gowther dies, many miracles are witnessed around his tomb.
