Not all hearts were glad of the Coronation of the new King Arthur, and in one breast the anger and bitterness ran deeper than most. Morgan, half-sister to Arthur, was whispered to be a sorceress and a Queen of the Fée or Faerie folk, thus was she known as Morgan Le Fay and feared by all who knew her. On the shadowed night of Arthur's conception, Morgan's father had been slain by King Uther -- all for the sake of Uther's desire for her mother Ygraine. For this reason Morgan hated her brother, and also for jealousy of Ygraine's joy at having a son to inherit her lands and titles. And so while brother and sister had never met, the emnity between them lay coiled like a snake, fuelled by Morgan's all-consuming desire to be rid of Arthur.

On the day of the Coronation, the young King's head was filled with flattery and congratulations from Britain's great men. Arthur had spent his youth in humble obscurity, with his highest hopes being to serve as a squire or perhaps one day become a Knight of the Realm. And so to suddenly discover that Royal blood flowed through his veins... well, it would make any boy reckless. Even Merlin's watchful eye did not see the secretive young maid who stole Arthur away to her chambers during the evening's celebrations. Arthur cared little who shared his bed, for he thought it merely the prerogative of a King. But when he emerged into Merlin's presence, arm in arm with his unbeknownst sister... Merlin was wroth, for he guessed Morgan's schemes, and sent her immediately away from the hall and back to her own castle. But the deed had been done, and Merlin knew that Arthur's shock and horror would surely have made him strike his sister down had she remained. And so for many months Merlin kept the secret from him, until rumours arose out of Morgan's proud gloating -- that she had borne a son sired by the new King.
Against the resigned counsel of Merlin, Arthur gathered a group of knights and set out for Tintagel swiftly upon the heels of these tales. But when he arrived at the cliff-perched fortress, he found the gates locked and barred, and Morgan's cold taunts ringing down from the battlements. In a rage, Arthur's men attacked the castle and overcame it, but they found not a single child inside, for Morgan had hidden her babe well. And then, in a deed more terrible for its purity of purpose, Arthur decreed that all children in the lands around Tintagel be gathered up and set in the fishermens' boats; when this was done, he ordered them all pushed out to sea, amidst the wailing of the babies' mothers. He did this in hopes of foiling Morgan's ruse -- but as the last of the hungry cries faded out over the waves, he knew he had committed a horrible sin. But he could do nothing more, and in his foolish pride he returned to Merlin and declared Morgan's threat ended.
So he thought for many years that this was true, and as he grew in wisdom and kingship he buried his sin deeper down so that he might not have to remember what he had done that dark day long ago. He denied it so fully that he did not recognize the family resemblance in a young man who came to join his court years later -- a young Knight by the name of Mordred, who would one day be his undoing.