When Tristan arrives in Cornwall, he learns that Morold, the brother-in-law of Gurmun, King of Ireland, is there to demand tribute from Cornwall and England under threat of an armed attack. The assembled lords draw straws to see who will have to forfeit their sons to serve Morold. Tristan interrupts the gathering and gives a speech saying that Mark and his lords should instead opt for war; he volunteers to duel Morold to spare others becoming Morold’s serfs. Mark tries to dissuade Tristan, but he persists.

Tristan asks Morold whether he prefers to solve the dispute by single combat or by war, and Morold chooses single combat with Tristan. Three days later, the two of them meet on a small islet close to the shore, with a crowd observing from the mainland. Tristan leaves his boat adrift, telling Morold that since only one of them will survive, the boat that Morold has brought will be enough.

The two charge at each other and shatter their spears on one another’s shields. The narrator says that although Morold has the strength of four men, Tristan also has God, justice, and “Willing Heart” on his side, also giving him the power of four.