Urien /ˈjʊəriɛn/, often referred to as Urien Rheged or Uriens, was a late 6th-century king of Rheged, an early British kingdom of the Hen Ogledd (northern England and southern Scotland). His power and his victories, including the battles of Gwen Ystrad and Alt Clut Ford, are celebrated in the praise poems to him by Taliesin, preserved in the Book of Taliesin. He became the "King Urien of Gorre" of later Arthurian legend and his son Owain mab Urien was later known as Ywain.
According to the genealogies, Urien was the son of Cynfarch Oer, son of Meirchion Gul, son of Gorwst, son of Cenau, son of Coel Hen (King Cole), the first recorded post-Roman military leader in the area of Hadrian's Wall. He fought against the rulers of the Anglian kingdom of Bernicia (modern Northumbria). An Anglian noble, Ida, had occupied Metcauld around the middle of the 6th century and begun to raid the mainland. Urien joined with other northern kings, Rhydderch Hael "the Generous" of Strathclyde and two other descendants of Coel, Gwallog mab Llaenog and Morgant Bwlch. They defeated the Angles and besieged them on Lindisfarne but, according to the Historia Brittonum, Urien was assassinated at the behest of Morgant Bwlch, who was jealous of his power. A man called Llofan Llaf Difo is said to have killed him. One of the Welsh Triads calls the death of Urien one of the "Three Unfortunate Assassinations" and another lists him as one of the "Three Great Battle-leaders of Britain".