A manuscript of the second half of the thirteenth century containing 'Y Gododdin', a series of awdlau lamenting warriors slain in battle at Catraeth, and believed to have been originally composed by Aneirin at the end of the sixth century (pp. 1-24). The awdlau are followed by four poems known as the gorchanau: Gorchan Tudfwlch (pp. 25-26), Gorchan Adebon (p. 26), Gorchan Cynfelyn (pp. 26-28) and Gorchan Maeldderw (pp. 28-38).
The manuscript was written by two scribes: scribe A (pp. 1.1-23.5, 25.1-30.11) and scribe B (pp. 23.6-24.21, 30.12-38.22). The hand of scribe B is also responsible for Peniarth MS 14, pp. 1-44 and Peniarth MS 17; see Ingo Mittendorf, 'Sprachliche und orthographische Besonderheiten eines mittelkymrischen Textes aus dem 13. Jahrhundert (Gwyrthyeu e Wynvydedic Veir)', in Akten des Zweiten Deutschen Keltologen-Symposiums, ed. S. Zimmer, R. Ködderitzsch and A. Wigger, Buchreihe der Zeitschrift für celtische Philologie, 17 (Tübingen, 1999), p. 129. Daniel Huws suggests the Cistercian abbey of Aberconwy as a likely location of the scriptorium; see Medieval Welsh Manuscripts (Cardiff and Aberystwyth, 2000), 75.