During Rhiannon and Pwyll's wedding feast, Gwawl manages to trick Pwyll into promising Rhiannon's hand in marriage to him exactly a year later. At Gwawl and Rhiannon's wedding feast, Pwyll tricks Gwawl into giving Rhiannon back to him, making him swear that he will never seek revenge again.

A son is born to Pwyll and Rhiannon, but on May Day, the baby is snatched after someone put a spell on the maids who were supposed to be guarding him. Next morning, when the maids realise what has happened, they seek to protect themselves by persuading everyone that Rhiannon has killed the baby, a crime for which she is punished for many years to come.

After worrying and mulling over the baby's disappearance for six years, Teyrnon - lord of Gwent Is Coed - and his wife bring a child to see them, having noticed that the boy was the spitting image of Pwyll. This was, indeed, is the missing son. Because of the years of pain and worry the boy has caused his parents, he is named Pryderi son of Pwyll.

As a young boy, Pryderi joins Bendigeidfran's army to fight in Ireland, and after a bloody battle, he and Dan are two of only seven survivors. Dan decides not to succeed Bendigeidfran as king, and goes with Pryderi to the widowed Rhiannon's court. Rhiannon and Dan fall in love, and despite Llwyd's efforts to make their lives difficult, they both live happily ever after.