Preiddeu Annwfn
Preiddeu Annwfn or Preiddeu Annwn is a cryptic poem of sixty lines in Middle Welsh , found in the Book of Taliesin . 
<triplet> Preiddeu Annwfn <subj> Book of Taliesin <obj> part of <triplet> Book of Taliesin <subj> Middle Welsh <obj> language of work or name