Sir Tristram’s madness in the forest begins when he discovers that La Beale Isoud has exchanged letters with Sir Kehydius, a young knight whom Tristram had brought into Cornwall. The discovery turns private heartbreak into public withdrawal: Tristram leaves Tintagil, refuses food and company, and lives for months in the wilderness, at times playing a harp and weeping. His eventual recognition by La Beale Isoud’s little brachet brings him back into the court’s reach, but also makes concealment impossible. The episode makes grief visible through a series of changes in Tristram’s conduct and appearance, while the harp and brachet preserve links to the life from which he has fled.

The discovery at Tintagil

Sir Tristram and La Beale Isoud are reunited secretly at King Mark’s court after Sir Dinas and Dame Bragwaine bring Tristram and Sir Kehydius into a chamber assigned by the queen. Kehydius, who has fallen in love with La Beale Isoud, has sent her letters and ballads; she has answered with a letter intended to comfort him. The two exchanges are private, but their discovery gives Tristram proof that his trust in La Beale Isoud has been broken.

The discovery occurs while King Mark is playing chess beneath the chamber. Tristram finds both Kehydius’s letter and the queen’s reply, confronts La Beale Isoud with them, and turns on Kehydius. He recalls that he brought Kehydius from Brittany and had won the lands of his father, King Howel. He also points to his own marriage to Kehydius’s sister, Isoud la Blanche Mains, as a bond that makes the perceived betrayal especially bitter. La Beale Isoud swoons, while Kehydius escapes by leaping from a window over King Mark’s head and excuses himself by claiming he had fallen asleep there.

Departure and withdrawal

Fearing discovery at court, Tristram arms himself in the tower and rides openly out of Tintagil once he sees no one will stop him. At the gate he encounters Gingalin, Sir Gawaine’s son, who challenges him. Tristram, carrying only a sword, knocks Gingalin from his horse and continues into the forest. King Mark witnesses the encounter and later learns from Gingalin only that the unknown knight was sighing and grieving; the scene establishes that Tristram’s sorrow is apparent even before his identity is known.

Tristram meets Sir Fergus in the forest and falls from his horse in a swoon. He remains overwhelmed for three days and nights. When a damsel sent by Sir Palamides finds him, she reports his condition to Sir Fergus, and La Beale Isoud herself is described as ill in bed with grief. The damsel tries to help Tristram, but her efforts intensify rather than relieve his distress. He repeatedly rides away from her, refuses the food and drink brought to him, and avoids the human company that might restore him to ordinary life.

His retreat lasts first a quarter of a year near a castle whose lady remembers him for his harp-playing. Tristram had taught her to play the instrument, and she sends it to him along with food and drink. At times, when the lady plays, he comes to listen; at other times he plays the harp himself and weeps. The instrument thus becomes a fragile connection to his former identity: music draws him near other people, but does not end his grief. Eventually he disappears again, leaving the lady unable to find him.

Life among the shepherds

Tristram’s withdrawal becomes a change in his outward life as well as his conduct. Naked and physically diminished, he falls in with herdsmen and shepherds, who give him food and drink. When he behaves badly, they beat him with rods and shear his hair, making him look like a fool. He remains in the forest, avoiding towns and villages, for a period that extends to half a year. The narrative moves from the noble knight’s sudden departure to his dependence on pastoral workers, marking how far he has fallen from the courtly world without suggesting that his skill or former standing has simply vanished.

Even in this altered state, traces of Tristram’s character and abilities remain. When Sir Dagonet, King Arthur’s fool, and his squires stop at a well to drink, their horses break loose. Tristram plunges Dagonet and the squires into the well, then catches the horses and returns them to their riders. The shepherds laugh at the incident. It is an irreverent episode, but it also shows Tristram acting decisively and capably while he continues to live outside settled society.

The same forest contains danger as well as comic encounters. Sir Dinant later tells King Mark that a naked man rescued him from the giant Tauleas at the fountain, describing the rescuer as the mad man of the forest. King Mark goes out with his hunters and finds Tristram lying beside the well with a sword. He orders his knights to approach gently, cover Tristram with mantles, and bring him to Tintagil. There, Tristram is bathed and given hot broth until he recovers his senses. No one at court recognizes him at first, so his return begins under a temporary anonymity that contrasts with his former public identity.

Recognition and consequence

La Beale Isoud hears that King Mark has brought a wild man from the forest and goes to see him with Dame Bragwaine. She cannot identify him, though she feels she has seen him before. Tristram recognizes her at once, turns his face away, and weeps. Recognition initially runs in only one direction: the man who has lost his place in the court still knows the queen, but the queen cannot yet name the man before her.

The little brachet resolves the uncertainty. La Beale Isoud has kept it since Tristram gave it to her when she first came to Cornwall; it had been sent to Tristram by the king’s daughter of France. When it catches his scent, it leaps upon him, licks his face, and searches over his hands and body. The animal’s recognition succeeds where La Beale Isoud’s memory has failed. Dame Bragwaine identifies him to the queen, and La Beale Isoud faints before blessing God that Tristram is alive.

The brachet’s fidelity also makes Tristram’s disguise untenable. La Beale Isoud warns him that King Mark will banish or destroy him if he recognizes him, and urges him to accept the king’s will and go to King Arthur’s court, where he is loved. She promises that she will continue to send word and remain at Tristram’s command, even if she must live poorly. Tristram refuses her approach and asks her to leave, saying that he has already escaped great anger and danger for her sake. His return to awareness therefore does not resolve the relationship’s conflict: recognition restores his name, but the letters and their consequences remain between the lovers, and the risk posed by King Mark still shapes what Tristram can do.