White Book of Rhydderch

The collection later passed to the newly established National Library of Wales as the Peniarth or Hengwrt-Peniarth Manuscripts.

Peniarth MS 5 (the first part of the original manuscript) contains Christian religious texts in Welsh, mostly translated from Latin and French, including Lives of various saints and a tale of Charlemagne.

The White Book was copied in the mid 14th century, most probably for Rhydderch ab Ieuan Llwyd (c. 1325–1400) from Parcrhydderch in the parish of Llangeitho in Ceredigion.

Rhydderch, who came from a family with a long tradition of literary patronage, held posts under the English Crown but was also an authority on native Welsh law.

The contents of the manuscript are very similar to the Red Book of Hergest, and may have been its exemplar; but it is more likely that the two descend from a lost common ancestor.