According to ancient legend, Glynn's son, Roan, the hero-poet, survived to the time of Patrick, two hundred years after the other Tuathans. On a certain occasion when the saint asked him how he had lived to such a great age, the old hero related the following story:
One day while out hunting with Glynn and the Tuathans, Roan saw a beautiful maiden on a white steed ride swiftly towards them. As she came slowly to the presence of Glynn, he addressed her courteously in these words,
"Who art thou, O lovely youthful princess? Tell us thy name and the name of thy country, and relate to us the cause of thy coming"
She answered in a sweet and gentle voice, "Noble king of the Tuatha, I am the daughter of the king of Tirna and my name is Mima of the Golden Hair. I love thy noble son Roan and this is what has brought me to Tuatha."
She took Roan on her white steed to Tirna the land of never-ending youth. The steed galloped swiftly and smoothly towards the west, till he reached the Kendraugh Sea. They moved over the face of the sea with the speed of a cloud-shadow on a March day. They visited many strange and beautiful places. At one of them the Land of Virtues Mima asked Roan to free a Tuatha Danann damsel from a Fomoor demon.
Roan fought him for three days and three nights without food or drink or sleep, he felled the giant and instantly cut off his head. He buried the giant in a deep and wide grave, and he raised a great stone over him with his name graved in Ogam.
On arriving in Tirna, Roan saw that it was the most delightful and most renowned country under the sun. There was an abundance of gold, silver and jewels, of honey and wine, and the trees bore fruit and blossoms and green leaves together all the year round. He wore the crown of the King of Tirna which guarded him day and night, and he was for ever young, and gifted with unfading beauty and strength and Mima of the Golden Hair became his wife.
Roan lived in the Land of Youth more than two hundred years. At the end of that time he had a longing to see his father Glynn and all his old companions. The king gave him permission and Mima said, "Tuatha is not now as it was when you left it." The great Glynn and his Tuathans are all gone; and you will find instead of them, a holy father and hosts of priests and saints. If once you alight from the white steed, you will never come back to me.
When Roan arrived back in Tuatha he scarcely knew the old places. He saw little men and women all mounted upon horses as small as themselves and they marveled much at his great size and the beauty and majesty of his person. He visited every place throughout the country where he knew the Tuathans had lived but he found their houses solitary and in ruins.
At length he came to Glensmole where many a time he had hunted in days of old with the Tuathans, and there he saw a crowd of people who said "Come to us, thou mighty hero, and help us out of out strait; for thou art a man of vast strength."
He went with them and found a number of men trying in vain to raise a large flat stone. It was half lifted from the ground, but those who were under it were not strong enough either to raise it further or to free themselves from its weight. And they were in great distress, and on the point of being crushed to death.
Roan stooped forward and seized the stone with one hand, and with his very last strength he flung the stone seven lengths from its place and relieved the little men. But with the great strain the golden saddle-girth broke, and bounding forward to keep himself from falling, he suddenly came to the ground on his two feet.
The moment the white steed felt himself free, he shook himself and neighed. Then, starting off with the speed of a cloud-shadow on a March day, he left Roan standing helpless and sorrowful. Instantly a woeful change came over Roan; the sight of his eyes began to fade, the ruddy beauty of his face fled, he lost all his strength and he fell to the earth a poor, withered old man, blind and wrinkled and feeble.
The white steed was never seen again. Roan never recovered his sight, his youth, or his strength; and he lived in this manner, sorrowing without ceasing for his gentle, golden-haired wife, Mima, and thinking ever of his father, Glynn and of the lost companions of his youth.