Urien
Urien (;  ), often referred to as Urien Rheged or Uriens, was a late 6th-century king of Rheged, an early British kingdom of the Hen Ogledd (today's northern England and southern Scotland) of the House of Rheged. In Arthurian legend, he inspired the character of King Urien of either Garlot (Garloth) or Gore (Gorre). His most famous son, Owain mab Urien, similarly turned into the character of Ywain. Biography
According to the genealogies, Urien, the king of Rheged, 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. Urien 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". Urien's 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 had at least five sons, named Owain, Rhiwallon, Elffin, Rhun 'Baladr Bras', and Pasgen, the eldest of whom (Owain mab Urien) succeeded him. Legend

Urien remained a popular figure in Wales over the centuries, and he and his son Owain were incorporated into Arthurian legend as it spread from Britain to continental Europe. In the legend of King Arthur, Urien is brother of King King Lot of Lothian. In chivalric romances, the location of his kingdom is transferred to either the Otherworldly and magical  (Gore) or a much less fantastic Garlot (Garloth). During the reign of Uther Pendragon (Arthur's father), Urien marries a sister or half-sister of the young Arthur, Morgan (sometimes another of Arthur's sisters is named as Urien's wife, such as Hermesan in the Livre d'Artus and Blasine in Of Arthour and of Merlin). He, like the kings of several other lands, initially opposes Arthur's accession to the throne after Uther's death. Urien and the others rebel against the young monarch (with Urien even briefly kidnapping Arthur's wife Guinevere in the Livre d'Artus), but upon their defeat, he is among the rebel leaders become Arthur's allies and vassals. His marriage to Morgan is not portrayed as a happy one, however, as in a popular version from the Post-Vulgate Cycle (also included in Thomas Malory's influential Le Morte d'Arthur) Morgan plots to use Excalibur to kill both Urien and Arthur and place herself and her lover Accolon on the throne. Morgan fails in all parts of that plan, being foiled by their own son and by the Lady of the Lake. Urien is usually said to be the father of Ywain (Owain) by Morgan but many texts also give him a second son, Ywain the Bastard, fathered on his seneschal's wife. Welsh tradition further attributes to him a daughter named Morfydd, daughter of Modron. According to Roger Sherman Loomis, the name and character of another Arthurian king, Nentres of Garlot (husband of Arthur's sister Elaine), could have been derived from that of Urien. Malory also sometimes spells Urien's name as Urience, which has led some later authors (e.g. Alfred Tennyson) to identify him with Arthur's relentless rival King Rience. In popular culture
 Urien is mentioned in the 20th-century Welsh awdl Yr Arwr by Hedd Wyn. He is a minor character in Mary Stewart's Merlin Trilogy. He appears as Uryens in John Boorman's film Excalibur (1981), depicted as an enemy lord who becomes Arthur's ally and is the one to knight him. He is one of the key characters in Melvyn Bragg's novel Credo (1996) (reprinted as The Sword and the Miracle in the USA), a celebration of the Celtic tradition and its fight against the Northumbrian and Roman (Catholic) incursions. References

6th-century English monarchs
6th-century Scottish monarchs
6th-century Welsh monarchs
6th-century murdered monarchs
Arthurian characters
Knights of the Round Table
Monarchs of Rheged
Taliesin