Sir Marhaus and the Duke of the South Marches meet in a compulsory combat born of the duke’s grievance against King Arthur’s court. The duke blames Sir Gawaine for the deaths of his seven sons and has sworn revenge on any knight of the court who comes within his reach. Marhaus, an Irish knight of the Round Table, accepts the challenge; by defeating the duke and his six remaining sons, he converts a personal feud into a pledge of political submission to Arthur.

The Duke’s Vow and the Encounter

Marhaus is travelling south with a damsel when night overtakes them in a deep forest. A man at a courtelage offers to take them to a place where they can find lodging, but does not explain the condition attached to that hospitality. At the castle, the duke receives Marhaus and asks his name, origin, and allegiance. Marhaus identifies himself as a knight of King Arthur and a member of the Round Table, born in Ireland. The duke replies that he resents Arthur and his fellowship and warns that he and his six sons will meet Marhaus the next morning.

The cause is not an immediate quarrel between the two men. The duke says that Sir Gawaine slew his seven sons in an encounter, and that he consequently vowed no knight of Arthur’s court would lodge with him or pass where he could confront him without facing revenge. The duke is identified as the Duke of the South Marches, a longstanding enemy of Arthur and his knights. His decision to make lodging conditional on combat turns the castle’s hospitality into an instrument of private retaliation.

The Combat

The next morning, the duke and his six sons meet Marhaus mounted and armed, each carrying a spear. The duke and two of his sons break their spears against Marhaus, who holds his own spear up and does not strike them. The remaining four sons then approach in pairs; their spears, too, break without Marhaus touching them. The sequence makes the imbalance plain before the fight’s decisive action: the duke’s party expends its first attacks, while Marhaus remains unhurt and in control of his response.

Marhaus then rides at the duke and knocks him and his horse to the ground. He deals with the sons in turn, dismounts, and demands the duke’s surrender, threatening to kill him if he refuses. When some of the sons recover and would renew the attack, Marhaus warns the duke to restrain them or face the full force of the fight. Seeing that he cannot escape defeat, the duke orders his sons to yield. They kneel and offer the pommels of their swords, and Marhaus accepts their submission.

Submission and Political Consequences

The surrender ends in more than a temporary victory. By common agreement, the duke and his sons promise that they will no longer be enemies of King Arthur. They also undertake to come at the following Whitsuntide and place themselves in the king’s grace. Their pledge gives Arthur a route to bring a hostile household back into his political order without the account describing a further battle or the duke’s death.

The episode’s resolution contrasts the duke’s vow of vengeance with the public allegiance secured after combat. The dispute began in retaliation for Sir Gawaine’s killing of the duke’s seven sons, but the immediate opponent is Sir Marhaus, who acts as a knight of Arthur’s court. The duke’s defeat therefore answers the personal challenge while also compelling a change in the family’s declared relation to the king. The promised appearance at Whitsuntide leaves that reconciliation to be completed through submission to Arthur’s authority.

Marhaus’s Wider Circuit of Deeds

The encounter forms one episode in Marhaus’s travels with the damsel, not an isolated appearance. After the duke and his sons yield, the damsel takes Marhaus within two days to a tournament called by Lady de Vawse. There he wins a gold circlet valued at a thousand besants and gains renown, having brought down forty knights at different times. The narrative thus places the settlement of a political feud beside a public tournament victory: in both settings Marhaus’s success earns recognition, though the outcomes differ, with the duke’s pledge serving Arthur’s realm and the circlet rewarding prowess.

Within the same travelling sequence, Marhaus later reaches the lands of Earl Fergus, where he is asked to confront the giant Taulurd, who has been destroying the earl’s lands. That later adventure extends the pattern of Marhaus answering local threats, but it is distinct from the South Marches encounter: the duke’s conflict arises from a vow against Arthur’s knights, and its outcome is the former enemies’ promise to seek the king’s grace.