Carteloise is a castle in the marches of Scotland where the Grail companions confront a custom that demands a maiden’s blood to treat a sick noblewoman. Its episode tests the companions’ refusal to accept violence as custom, then reveals that Percivale’s sister will freely undertake the sacrifice the castle’s inhabitants had tried to impose.

Setting and Arrival

After Galahad takes the sword with the strange girdles and Percivale’s sister provides its specially made girdle, the companions leave one ship and are carried by the wind to Carteloise. They arrive without provisions, and the sister warns that the castle’s inhabitants would attack them if they knew the travelers belonged to King Arthur’s household. A squire recognizes their affiliation and returns to the fortress; soon a horn sounds and a gentlewoman warns them that they have come to their deaths. The companions refuse to turn back, trusting in the divine service they have undertaken.

The Castle Custom and Resistance

Armed knights confront Galahad, Percivale, and Bors, demanding that the maiden accompanying them yield the castle’s custom. The required offering is a dish full of blood from her right arm. Percivale insists that a maiden should be free wherever she goes, and Galahad declares that the castle will not take this woman while he lives. Bors and Percivale likewise accept the risk rather than consent to the demand.

The three companions fight first against ten or twelve knights and overcome them. A larger force then approaches, but the castle’s knights acknowledge that the travelers are formidable and invite them to lodge for the night, promising to leave them in the condition in which they found them. The offer pauses the immediate battle without resolving the custom: the companions are told that, once they know its purpose, they will agree to it.

The Sick Noblewoman and the Sacrifice

The castle’s inhabitants explain that their lady has long been ill and that no physician has cured her. An old man had said that she could recover if an entire dish of blood were taken from a maiden who was both a king’s daughter and pure in intention and deed, and that the blood were used to anoint her. The custom was established to obtain this remedy.

Percivale’s sister judges that the sick woman will otherwise die and offers to provide the blood. Galahad warns that she herself may die from giving so much, but she accepts that possibility, believing the act will bring spiritual benefit and honor to her lineage. Her decision ends the prospect of renewed fighting over the custom: the companions’ earlier resistance was to its forced demand, while the sister’s offering is made of her own choice.

Consequences and Narrative Significance

The next morning, after the companions hear mass, the sick woman is brought out. Percivale’s sister gives enough blood to fill the dish, blesses the patient, and asks her to pray for her as she approaches death. Galahad and his companions try to help her, but she has lost too much blood to survive. The castle episode thus joins a miraculous cure sought for one woman to the death of another, making sacrifice, rather than victory in combat, its decisive outcome.

Carteloise is consequently defined in the narrative by the custom that governs passage through its territory and by the moral reversal that follows: the companions will not allow the maiden to be seized, yet she chooses to give what the castle demanded. The location’s significance lies in this distinction between coercion and voluntary service, and in the cost the tale attaches to healing the sick noblewoman.