Cumhal was killed in the battle, and within that year the king's daughter had a son. By command of his grandfather, the boy was thrown out of the castle window into a loch, to be drowned, on the day of his birth.
The boy sank from sight; but after remaining a while under the water, he rose again to the surface, and came to land holding a live salmon in his hand.
The grandmother of the boy, Cumhal's mother, stood watching on the shore, and said to herself as she saw this: "He is my grandson, the true son of my own child," and seizing the boy, she rushed away with him, and vanished, before the king's people could stop her.
When the king heard that the old woman had escaped with his daughter's son, he fell into a terrible rage, and ordered all the male children born that day in the kingdom to be put to death, hoping in this way to kill his own grandson, and save the crown for himself.
After she had disappeared from the bank of the loch, the old woman, Cumhal's mother, made her way to a thick forest, where she spent that night as best she could. Next day she came to a great oak tree. Then she hired a man to cut out a chamber in the tree.
When all was finished, and there was a nice room in the oak for herself and her grandson, and a whelp of the same age as the boy, and which she had brought with her from the castle, she said to the man: "Give me the axe which you have in your hand, there is something here that I want to fix."
The man gave the axe into her hand, and that minute she swept the head off him, saying: "You'll never tell any man about this place now." One day the whelp ate some of the fine chippings (bran) left cut by the carpenter from the inside of the tree. The old woman said: "You'll be called Bran from this out."
All three lived in the tree together, and the old woman did not take her grandson out till the end of five years; and then he couldn't walk, he had been sitting so long inside.
When the old grandmother had taught the boy to walk, she brought him one day to the brow of a hill from which there was a long slope. She took a switch and said: "Now, run down this place. I will follow and strike you with this switch, and coming up I will run ahead, and you strike me as often as you can."
The first time they ran down, his grandmother struck him many times. In coming up the first time, he did not strike her at all. Every time they ran down she struck him less, and every time they ran up he struck her more.