King Arthur is the British king whose legends, especially those regarding the Knights of the Round Table, evolved significantly during the Middle Ages in most European countries, but especially France, Germany and England.
It’s long been disputed whether a true King Arthur existed and there is some evidence that in the 5th century CE, there was an Arthur, possibly Roman or Celtic, who was able to lead a successful battle or succession of battles to turn back Saxon invaders. The Arthur that we know from myths and legends is much more fancifully rendered, and first mention of the fictional character occurs in History of the Kings of Britain by the 11th and 12th century clergyman, Geoffrey of Monmouth.
The basic legend is that this British king is the son of Uther Pandraeg, and Igraine, the wife of Gorlois. Utherfalls in love with Igraine, and with the counsel of the wizard Merlin, comes to her disguised as her husband. Due to Arthur’s parentage he is raised as a ward of another knight, and only learns about his parentage after Uther’s death. It is as this point that many accounts have the young and assumedly illegitimate child claiming his kingship by removing Excalibur, the great and enchanted sword, from a stone, a feat that can only be achieved by the true king.
As king, Arthur gathers together a group of knights who fight for justice, and establishes the Knights of the Round Table. Among the quests, depending upon each story, is the search for the Holy Grail. Moreover, the knights are enjoined to protect women and the helpless, a significant change from some of the abuses of lords and knights to vassals in the feudal system. Another key element to the legends is Arthur’s establishment of Camelot, the fair kingdom he builds.
Arthur is married to the childless Guinevere, though various accounts give him illegitimate children, including a son, Mordred, who ultimately kills his father (and is killed by him) and overturns his kingdom. Mordred’s story and his relationship to his father is an exceptionally sad one in some accounts, since Mordred is the product of an incestuous liaison between the king and his half-sister. The kindest accounts do not mention this, or defend the king by suggesting he is unaware of Morgase’s relationship to himself, and in very early accounts, Mordred is not Arthur’s son.
The tales of king and Camelot are retold numerous times, and underwent significant changes as the Middle Ages progressed. Emphasis in tales outside of England was often on adding additional knights, like Lancelot, Parzival, and Gawain. Some feel the best take on the whole story is Thomas Mallory’s Le Morte D’Arthur published in the late 15th century.
Others prefer modern renderings of Arthurian tales, including works like T.H. White’s The Once and Future King, Marion Zimmer Bradley’s The Mists of Avalon, and Mary Stewart’s Merlin Trilogy. Numerous films have dealt with the king too. The most recent of these, King Arthur made in 2004, does attempt to restore some historical accuracy to the tale by dating the time as not during the Middle Ages, but instead taking place during the 5th century CE, when the true Arthur may have actually reigned.