Black Book of Carmarthen

The Black Book of Carmarthen (Welsh: Llyfr Du Caerfyrddin) is thought to be the earliest surviving manuscript written solely in Welsh. The book dates from the mid-13th century; its name comes from its association with the Priory of St. John the Evangelist and Teulyddog at Carmarthen, and is referred to as black due to the colour of its binding. It is currently part of the collection of the National Library of Wales, where it is catalogued as NLW Peniarth MS 1.

This was one of the collection of manuscripts amassed at the mansion of Hengwrt, near Dolgellau, Gwynedd, by Welsh antiquary Robert Vaughan (c.1592–1667); the collection later passed to the newly established National Library of Wales as the Peniarth or Hengwrt-Peniarth Manuscripts. It is believed that the manuscript is first recorded when it came into the possession of Sir John Price of Brecon (1502?–1555), whose work was to search the monasteries dissolved by Henry VIII. It was given to him by the treasurer of St David's Cathedral, having come from Carmarthen Priory. Llyfr Du Caerfyrddin was described by William Forbes Skene (1809–92) as one of the Four Ancient Books of Wales.