Aneirin, Aneurin or Neirin mab Dwywei (c. 525 - 600) was a British poet, who has been taken by Thomas Stephens (1821-1875), the editor and translator of Aneurin's principal epic poem "Y Gododdin", for a son of Gildas, the historian. Y Gododdin is an account of the British defeat (603) by the Saxons at Cattraeth (identified by Stephens with Dawstane in Liddesdale ), where Aneurin is said to have been taken prisoner; but the poem is very obscure and is differently interpreted. It was translated and edited by W. F. Skene in his Four Ancient Books of Wales (1866), and Stephens' version was published by the Cymmrodorion Society in 1888. Aneirin is believed to have been a court poet or bard in one of the Brythonic kingdoms of southern Scotland, and wrote in Old Welsh, from which the modern Welsh language is descended. The version of the Llyfr Aneirin which survives today renders his work into mediaeval Welsh.