Iorwerth ab Owain Gwynedd or Iorwerth Drwyndwn (1145-1174), meaning "the broken-nosed", was a legitimate son of Owain Gwynedd (the king of Gwynedd) and his first wife Gwladys (Gladys) ferch Llywarch. Owain Gwynedd (in English " Owen " (c 1100&ndash November 28, 1170) alternatively known by the Patronymic " Owain ap Gruffydd Gwynedd (pr) is one of several Welsh Successor states that emerged in 5th-century post-Roman Britain. He married Marared ferch Madog. Madog ap Maredudd (died 1160 was the last Prince of the entire Kingdom of Powys, Wales and for a time held the Fitzalan Lordship of Oswestry His son Llywelyn the Great eventually united the realm and became known as Llywelyn Fawr and is one of Wales's most famous monarchs. Genealogy and early life Llywelyn was born about 1173 the son of Iorwerth ap Owain and the grandson of Owain Gwynedd, who had been ruler of Gwynedd until his death Iorwerth was killed in battle at Pennant Melangell, in Powys, during the wars deciding the succession following the death of his father.