The Cyfnerth redaction has seven manuscripts, U, V, W, X, Y, Z and Mk. The Cyfnerth redaction is often seen to be the oldest redaction of the three as far as the content is concerned. Previously the Gwentian code, the Cyfnerth redaction is named after Cyfnerth ap Morgeneu, who is named in a note appended to the Prologue in the Cyfnerth redaction manuscripts.
See also the list of texts.
Jones, Glanville R. J., ‘The Models for Organisation in Llyfr Iorwerth and Llyfr Cyfnerth’, Bulletin of the Board of Celtic Studies 39 (1992), 95-118.