Book I - Chapter XXVII - How all the children were sent for that were born on May-day, and how Mordred was saved.
THEN King Arthur let send for all the children born on May-day, begotten of lords and born of ladies; for Merlin told King Arthur that he that should destroy him should be born on May-day, wherefore he sent for them all, upon pain of death; and so there were found many lords' sons, and all were sent unto the king, and so was Mordred sent by King Lot's wife, and all were put in a ship to the sea, and some were four weeks old, and some less. And so by fortune the ship drave unto a castle, and was all to-riven, and destroyed the most part, save that Mordred was cast up, and a good man found him, and nourished him till he was fourteen year old, and then he brought him to the court, as it rehearseth afterward, toward the end of the Death of Arthur. So many lords and barons of this realm were displeased, for their children were so lost, and many put the wite on Merlin more than on Arthur; so what for dread and for love, they held their peace. But when the messenger came to King Rience, then was he wood out of measure, and purveyed him for a great host, as it rehearseth after in the book of Balin le Savage, that followeth next after, how by adventure Balin gat the sword.
Explicit liber primus. Incipit liber secundus