"Heddwyn" did not become a male Welsh name until after WWI. A young man who won the Welsh national poetry championship, (Eisteddfod) one of the most coveted honors in Wales, in 1917 bore the pen-name of "Hedd Wyn". However, by the time of the competition, he had already been drafted into the English army. Six weeks prior to being named as champion, Hedd Wyn had died in action overseas. His story grieved the entire nation. Welsh parents began to christen children with the name "Heddwyn" in his honor.
― Anonymous User 2/8/2005
2
To add to the information given above, the poet whose Bardic name was Hedd Wyn, and who was posthumously awarded the Chair at the Eisteddfod of 1917, was Ellis Evans of Trawsfynydd (1887-1917). A Welsh-language film about his life was made in 1992. The name 'Hedd' ('Peace') alone is also in current use in Wales.