Who is Davydd ap Llewelyn from Falls the Shadow and what is their importance?

Davydd ap Llewelyn was Fawr's only legitimate son. He was named sole heir as a teenager and lived most of his life expecting to become the Prince of Wales. Davydd, in fact, was the first man ever called Prince of Wales. When Llewelyn Fawr died, Davydd was forced to make peace with England in order to focus on a civil war with his brother Gruffydd. He tricked his brother into a meeting and then druged him to take him prisoner. Gruffydd's wife then used the king of England to get back at Davydd. When he was forced into surrendering, Davydd gave Gruffydd to the English King, making him a prisoner of England once again. Davydd died of cancer soon after his imprisonment.