The seneschal struck Joseph of Arimathea in the thighs with a sword, when Joseph wandered into a Saracen castle in the forest of Broceliande. Half of the sword broke off and remained in the wound. After he converted the castle and its lord, Matagran, he miraculously removed the broken piece of metal from his thighs, and proclaimed that the two halves would not be rejoined until the one handle it would come and achieve the Grail. The broken sword was held in great honor at Mategran'ts castle, at least for a while.
Malory omits this early history of the sword, but tells how Eliazar, Pellam's son, brought it to Carbonek and to Galahad and his companions to attempt mending it. After Bors and Percivale tried unsuccessfully, Galahad soldered the broken pieces by simply setting them together with his hands. Kissing the sword would keep whomever kissed it safe from being mortally wounded for the day.
Galahad found them during the Grail Quest. Meanwhile, the piece which had been stuck in Joseph dripped blood constantly. After Gawaine, Perceval, and Bors failed, Galahad successfully mended the sword at the end of the Grail Quest. Galahad gave it to Bors. Its tale recalls the Grail Sword and the Bleeding Lance.