Manawydan fab Llŷr

Manawydan fab Llŷr is a figure of Welsh mythology, the son of Llŷr and the brother of Brân the Blessed and Brânwen. The first element in his name is cognate with the stem of the name of the Irish sea god Manannán mac Lir, and likely originated from the same Celtic deity as Manannán. Unlike Manannán, however, no surviving material connects him with the sea in any way except for his patronymic (llŷr is an old Welsh word for sea). Manawydan's most important appearances occur in the Second and Third Branches of the Mabinogi (the later of which is named for him), but he is also referenced frequently in medieval poetry and the Welsh Triads.

Manawydan is an important character in the Second Branch of the Mabinogi, the Mabinogi of Brânwen, Daughter of Llŷr. In this tale, Manawydan serves as advisor to his brother Brân the Blessed, the King of Britain. He sits beside Brân at the feast celebrating the wedding of their sister Brânwen to Matholwch, king of Ireland, an occasion which is meant to solidify an alliance. When their half-brother Efnisien, upset that he has not been consulted, mutilates Matholwch's horses, Brân sends Manawydan to offer recompense. Later, when word gets back to Britain that Matholwch has been mistreating Brânwen, Manawydan joins Brân's rescue effort.

In the ensuing war, Manawydan is one of only seven men to survive. The mortally wounded Brân asks Manawydan and the others to cut off his head and take it back to Britain; it will continue speaking and keeping them company in the meantime. They come to a wondrous castle on the island of Gwales, where they enjoy a great feast and forget their sorrows. Manawydan recognizes opening the door of the castle "facing Cornwall" will break the spell, but one day his companion Heilyn son of Gwyn grows overcurious and opens it, and all their sorrows return. The group takes Brân's head to the White Hill (the location of the Tower of London) and bury it there, where it serves as a talisman against foreign invasion.

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