"But know ye," said the king, "this Irish knight will fight with none who be not come of royal blood and near of kin to kings or queens, as he himself is, for his sister is the Queen of Ireland."
Then said Tristram, "Let him know that I am come both on my father's and my mother's side of blood as good as his, for my father is King Meliodas and my mother was that Queen Elizabeth, thy sister, who died in the forest at my birth."
When King Mark heard that he welcomed him with all his heart, and knighted him forthwith, and made him ready to go forth as soon as he would choose, and armed him royally in armor covered with gold and silver.
Then he sent Sir Marhaus word, "That a better man than he should fight with him, Sir Tristram of Lyonesse, son of King Meliodas and of King Mark's own sister." So the battle was ordained to be fought in an island near Sir Marhaus' ships, and there Sir Tristram landed on the morrow, with Governale alone attending him for squire, and him he sent back to the land when he had made himself ready.
When Sir Marhaus and Sir Tristram were thus left alone, Sir Marhaus said, "Young knight Sir Tristram, what doest thou here? I am full sorry for thy rashness, for ofttimes have I been assailed in vain, and by the best knights of the world. Be warned in time, return to them that sent thee."
"Fair knight, and well-proved knight," replied Sir Tristram, "be sure that I shall never quit this quarrel till one of us be overcome. For this cause have I been made knight, and thou shalt know before we part that though as yet unproved, I am a king's son and firstborn of a queen. Moreover I have promised to deliver Cornwall from this ancient burden, or to die. Also, thou shouldst have known, Sir Marhaus, that thy valor and thy might are but the better reasons why I should assail thee; for whether I win or lose I shall gain honor to have met so great a knight as thou art."
Then they began the battle, and tilted at their hardest against each other, so that both knights and horses fell to the earth. But Sir Marhaus' spear smote Sir Tristram a great wound in the side. Then, springing up from their horses, they lashed together with their swords like two wild boars. And when they had stricken together a great while they left off strokes and lunged at one another's breasts and visors; but seeing this availed not they hurtled together again to bear each other down.
Thus fought they more than half the day, till both were sorely spent and blood ran from them to the ground on every side. But by this time Sir Tristram remained fresher than Sir Marhaus and better winded, and with a mighty stroke he smote him such a buffet as cut through his helm into his brain-pan, and there his sword stuck in so fast that thrice Sir Tristram pulled ere he could get it from his head. Then fell Sir Marhaus down upon his knees, and the edge of Sir Tristram's sword broke off into his brain-pan. And suddenly when he seemed dead, Sir Marhaus rose and threw his sword and shield away from him and ran and fled into his ship. And Tristram cried out after him, "Aha! Sir knight of the Round Table, dost thou withdraw thee from so young a knight? it is a shame to thee and all thy kin; I would rather have been hewn into a hundred pieces than have fled from thee."
But Sir Marhaus answered nothing, and sorely groaning fled away.
"Farewell, Sir knight, farewell," laughed Tristram, whose own voice now was hoarse and faint with loss of blood; "I have thy sword and shield in my safe keeping, and will wear them in all places where I ride on my adventures, and before King Arthur and the Table Round."