Peniarth Manuscripts in the context of William Watkin Edward Wynne

The White Book of Rhydderch (Welsh: Llyfr Gwyn Rhydderch, National Library of Wales, Peniarth MS 4-5) is one of the most notable and celebrated surviving manuscripts in Welsh. Mostly written in southwest Wales in the middle of the 14th century (c. 1350) it is the earliest collection of Welsh prose texts, though it also contains some examples of early Welsh poetry. It is now part of the collection of the National Library of Wales, having been preserved in the library at Hengwrt, near Dolgellau, Gwynedd, of the 17th century antiquary Robert Vaughan, who inherited it from the calligrapher John Jones and passed it to his descendants. The collection later passed to the newly established National Library of Wales as the Peniarth or Hengwrt-Peniarth Manuscripts.

What was one manuscript was divided into two in the medieval period and has been bound as two separate volumes, known as Peniarth MS 4 and Peniarth MS 5. Peniarth MS 4 contains the most important material: medieval Welsh tales now collectively known as the Mabinogion. 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 Statute of Rhuddlan (Welsh: Statud Rhuddlan), also known as the Statutes of Wales (Latin: Statuta Walliae or Valliae) or as the Statute of Wales (Latin: Statutum Walliae or Valliae), was a royal ordinance by Edward I of England, which gave the constitutional basis for the government of the Principality of Wales from 1284 until 1536.

The statute followed the Conquest of Wales by Edward I and the killing of the last Welsh prince to rule the whole Principality, Llywelyn ap Gruffudd in 1282. The statute introduced English common law to Wales, but also permitted the continuance of Welsh legal practices within the Principality. The statute also introduced the English shire system to the Principality of Wales. Prior to the statute, the Welsh principalities were ruled by Welsh law and the native Princes of Wales.

Hengwrt (Welsh for 'old court') was a mansion near Dolgellau in Meirionnydd, Gwynedd. It lay in the parish of Llanelltyd near the confluence of the River Mawddach and River Wnion, near Cymer Abbey. With medieval origins, it was rebuilt or remodelled on several occasions before being demolished in 1962. It is remembered as the original home of the important collection of the Peniarth Manuscripts, now in the National Library of Wales.

Robert Powell Vaughan (1592? – 16 May 1667) was an eminent Welsh antiquary and collector of manuscripts. His collection, later known as the Hengwrt–Peniarth Library from the houses in which it was successively preserved, formed the nucleus of the National Library of Wales, and is still in its care.