The Mabinogion is a collection of prose stories from medieval Welsh manuscripts. They are partly based on early medieval historical events, but almost certainly hark back to older Iron Age traditions. Its name comes from a misunderstanding made by the Mabinogions first English translator, Lady Charlotte Guest: she found at the end of the first tale the form mabynnogyon, a scribal error that was assumed to be the plural of the Welsh word mabinogi, which occurs correctly at the end of the remaining three of the Four Branches. The word mabinogi itself is something of a puzzle, although it is...