Pwyll Pendefig Dyfed — Pwyll, Prince of Dyfed — opens the First Branch of the Mabinogi by accidentally crossing Arawn, king of Annwn, during a hunt. To make amends he agrees to swap places with Arawn for a year and a day, ruling the otherworld in Arawn's shape while Arawn rules Dyfed in his. The two men become close friends. When Pwyll returns home he finds his kingdom better governed than he left it, and he and Arawn remain bound to one another for the rest of his life. From that point on Pwyll is known as Pwyll Pen Annwn — Pwyll, Head of Annwn.
It is shortly afterwards that Rhiannon rides past.
Pwyll is sitting on the Gorsedd Arberth, a low mound near his court at Arberth that is said to show strange wonders to any prince who sits on it. A woman in shining gold silk rides past at a walking pace, on a pale horse, going slowly down the road. Pwyll sends a man on foot after her; the man cannot catch her. The next day Pwyll sends his fastest horseman; the horseman gallops his horse until it nearly bursts, and still falls further behind. The horse on which she rides never quickens, never slows.
On the third day, Pwyll mounts his own best horse and rides after her himself. He cannot close on her either. At last, exhausted, he calls out — 'Lady, for the sake of the man you love best, wait.' She stops at once and turns, smiling. 'Gladly,' she says, 'and it would have been kinder to your horse if you had asked sooner.'
Her name is Rhiannon. She has come from the otherworld specifically to find him, because she does not want to be married to the man her family has chosen, Gwawl ap Clud. She and Pwyll arrange a wedding, but Pwyll — out of generosity and stupidity — promises a request to a stranger at the feast, and the stranger turns out to be Gwawl, who asks for Rhiannon. It takes Rhiannon's wit, a magic bag that can never be filled, and a beating-game called 'Badger in the Bag' to recover the situation. They marry. They have a son.
And then the son disappears in the night, and Rhiannon's six handmaidens, terrified of being blamed, smear the queen's mouth and hands with puppy-blood and accuse her of devouring her own child. The court believes them. Rhiannon — daughter of the otherworld, capable of crossing between worlds at a walking pace — accepts the penance laid on her: for seven years she must sit at the horse-block outside the gate of Arberth, tell her story to every stranger who arrives, and offer to carry them on her back into the court like a horse.
She does it. She does not protest. She does not flee. Years later the child is recovered — he has been stolen by a monster and raised by a kindly nobleman — and he is given the name Pryderi, 'care' or 'anxiety,' for what his mother went through. Rhiannon is restored to her place.
What makes the First Branch unforgettable is that it is, at heart, a story about asking. Pwyll cannot catch Rhiannon until he asks. He cannot keep her until he learns to listen. And Rhiannon, the woman who came down from the otherworld at a walking pace because she had chosen him, accepts an unjust punishment in silence — and is the one, in the end, whose patience holds the story together.
Wear something inspired by Pwyll and Rhiannon and you wear the oldest love story in Welsh literature — a prince humble enough to ask, an otherworld queen patient enough to wait, and a pale horse that no one can catch until they are spoken to.