[W Llyfr Gwyn Rhydderch].
Great collection of medieval Welsh prose, copied on parchment c.1325, containing versions of the Mabinogi and all the other narratives included in the Mabinogion, except Breuddwyd Rhonabwy [The Dream of Rhonabwy], and many religious texts. In compiling her translation, The Mabinogion (1846), Lady Charlotte Guest relied on the later Red Book of Hergest (c.1382–1410). The transcriber of the White Book is not known, but dialect evidence suggests he was from Deheubarth in south-western Wales. The name Rhydderch alludes both to Parc Rhydderch, a house where poetry was patronized, and to Rhydderch ab Ieuan Llwyd, master of Parc Rhydderch, who apparently owned the Book in the late 14th century. The White Book, now in two volumes, was rebound in white leather in 1940 at the National Library of Wales, where it is now kept. See J. Gwenogvryn Evans, The White Book Mabinogion (Pwllheli, 1907); Rachel Bromwich et al. (eds.), The Arthur of the Welsh (Cardiff, 1991), 9 ff.