He was the son of King Caradoc of Wales. The latter was succeeded by Griffith who had secured the throne by murder. Griffith sent Meriadoc and his sister Orwen to the woods to be killed, but the executioners did not carry out their task. Meriadoc was subsequently raised by Ivor the Huntsman and his wife Morwen.
Meriadoc went to Arthur's court and, with that King's help, he ousted Griffith and gained his rightful throne which he handed over to Urien. Meriadoc went abroad and rescued the daughter of the Emperor of Germany from Gundebald, King of the Land From Which No One Returns, and married her.