When Tristan came back to that land, King Mark and all his Barony were mourning; for the King of Ireland had manned a fleet to ravage Cornwall, should King Mark refuse, as he had refused these fifteen years, to pay a tribute his fathers had paid. Now that year this King had sent to Tintagel, to carry his summons, a giant knight; the Morholt, whose sister he had wed, and whom no man had yet been able to overcome: so King Mark had summoned all the barons of his land to Council, by letters sealed.
On the day assigned, when the barons were gathered in hall, and when the King had taken his throne, the Morholt said these things: "King Mark, hear for the last time the summons of the King of Ireland, my lord. He arraigns you to pay at last that which you have owed so long, and because you have refused it too long already he bids you give over to me this day three hundred youths and three hundred maidens drawn by lot from among the Cornish folk. But if so be that any would prove by trial of combat that the King of Ireland receives this tribute without right, I will take up his wager. Which among you, my Cornish lords, will fight to redeem this land?"
The barons glanced at each other but all were silent.
Then Tristan knelt at the feet of King Mark and said: "Lord King, by your leave I will do battle."
And in vain would King Mark have turned him from his purpose, thinking, how could even valour save so young a knight? But he threw down his gage to the Morholt, and the Morholt took up the gage.
On the appointed day he had himself clad for a great feat of arms in a hauberk and in a steel helm, and he entered a boat and drew to the islet of St. Samson's, where the knights were to fight each to each alone. Now the Morholt had hoisted to his mast a sail of rich purple, and coming fast to land, he moored his boat on the shore. But Tristan pushed off his own boat adrift with his feet, and said: "One of us only will go hence alive. One boat will serve."
And each rousing the other to the fray they passed into the isle.
No man saw the sharp combat; but thrice the salt sea-breeze had wafted or seemed to waft a cry of fury to the land, when at last towards the hour of noon the purple sail showed far off; the Irish boat appeared from the island shore, and there rose a clamour of "the Morholt!" When suddenly, as the boat grew larger on the sight and topped a wave, they saw that Tristan stood on the prow holding a sword in his hand. He leapt ashore, and as the mothers kissed the steel upon his feet he cried to the Morholt's men: "My lords of Ireland, the Morholt fought well. See here, my sword is broken and a splinter of it stands fast in his head. Take you that steel, my lords; it is the tribute of Cornwall."