Iorwerth ab Owain Gwynedd (or Iorwerth Drwyndwn meaning "the broken-nosed"), also called Edward (1145–1174), was the eldest legitimate son of Owain Gwynedd (the king of Gwynedd) and his first wife Gwladys (Gladys) ferch Llywarch. He married Marared ferch Madog. His son Llywelyn the Great eventually united the realm and became known as Llywelyn Fawr and is one of Wales's most famous monarchs. Iorwerth was killed in battle at Pennant Melangell, in Powys, during the wars deciding the succession following the death of his father.
- J. E. Lloyd, A History of Wales from the Earliest Times to the Edwardian Conquest (London, 1911; subsequent reprints)