Balin was born in Northumberland, a knight of proven valour who had the misfortune to kill a cousin of King Arthur in battle. For this deed he spent six months in Arthur's prison, and when he was released he found himself dressed in beggar's clothing, his status as a knight in ruins. His luck seemed to change when a mysterious damsel arrived at Camelot wearing a sword in a scabbard that she declared could only be drawn by the most virtuous knight in the land. King Arthur tried and failed. Every knight at court tried and failed. Balin, still in his prison rags, asked for a chance, and the damsel reluctantly agreed. He drew the blade as easily as drawing breath. The damsel begged him to return it, warning that if he kept it he would kill his greatest friend and bring about his own destruction. Balin refused. He had won the sword by right, and he would not part with it. From that moment, his fate was sealed.

Tragedy followed him like a shadow. As Balin prepared to leave Camelot, the Lady of the Lake arrived at court and demanded either Balin's head or the head of the damsel who had brought the sword, claiming that Balin had slain her brother. King Arthur tried to put her off, but Balin, hearing that she was asking for his head and remembering that she had caused his mother to be burned alive, strode forward and struck off her head with a single blow. Arthur, furious at the murder in his hall, dismissed Balin from the court. On the road, Balin was challenged by Sir Lanceor of Ireland, a knight jealous that he had not been the one to draw the enchanted sword. Balin killed Lanceor in the first joust. Lanceor's lady, Colombe, finding her lover dead, fell upon his sword and killed herself as Balin watched in helpless horror. It was the first of many deaths that would accumulate around him like fallen leaves.

Balin then met his brother Balan, who had also fallen out of favour with Arthur, and together they resolved to win back the king's love by capturing King Rience of North Wales, a rebel who had refused to acknowledge Arthur's sovereignty. With Merlin's guidance they ambushed Rience on the road, bound him, and dragged him before Arthur. The capture of Rience triggered a great battle at Castle Terrabil, where Arthur faced an alliance of twelve rebel kings. Balin and Balan fought with such fury that Merlin himself told Arthur they were two marvellous knights, and that Balin surpassed in prowess any knight the king had ever found. The battle was won, the rebel kings were slain, and for a brief moment it seemed that Balin's fortunes had turned.

But the curse of the sword was not finished with him. Soon after, Balin set out to avenge a knight named Sir Herlews le Berbeus, who had been murdered by Sir Garlon, the invisible brother of King Pellam. Garlon rode unseen in enchanted armour and struck down knights at random, a murderer who could not be fought because he could not be seen. Balin tracked Garlon to Pellam's castle and killed him at a feast with a single blow to the back of the head. Pellam, enraged at the death of his brother, attacked Balin immediately. Balin's sword broke against Pellam's armour, and he fled from room to room, searching for any weapon he could find. In a bedchamber he seized a spear that lay beside a sleeping figure, turned, and thrust it into Pellam. The spear was the Holy Lance, the weapon that the Roman soldier Longinus had used to pierce the side of Christ on the cross. The blow was the Dolorous Stroke. At the instant of impact, Pellam's castle shook and collapsed, the roof and walls crashing down upon them both. The land of Listenois withered into the Wasteland, its crops failing, its people dying, its fertility destroyed. Balin lay buried in the rubble for three days until Merlin dug him out and sent him on his way.

The final act of Balin's tragedy took place at an island castle where a custom compelled every passing knight to joust with the guardian of the bridge. Balin accepted the challenge, swapping his own shield for a better one just before the fight. The guardian, in red armour with an unrecognisable shield, was his own brother Balan, who had killed the previous guardian and been cursed to take his place. Neither brother knew the other. They fought for hours, matching blow for blow, until both were mortally wounded. Only as they lay dying in each other's arms did they recognise the voices and faces of their own blood. Balan died first. Balin lived only a few hours longer, long enough to be laid in the same tomb beside his brother. Merlin took the enchanted sword that had caused it all and set it in a block of marble, which he cast upon the water. Years later, at the beginning of the Grail Quest, Sir Galahad would draw that same sword from the stone, and the curse would pass to a new generation.