From Gwyn ap Nudd and the Old North
"Gwyn is a king of Annwn and is said to ‘contain’ (literally to hold within and to hold back) the fury of the spirits of Annwn. These are chthonic spirits, referred to today as ‘fairies, who play a role in mediating between this-world and the otherworld, the living and dead. Because of this intermediary role they have a deep concern for the land and the way we maintain our heritage. Their concerns are Gwyn’s."
Before now I haven't been one to repost from other people's blogs and point to them too much. That really need to change as there I so much good stuff being posted out there on subjects and Gods which are close to me. So go check out Lorna's blog post.