Arthur, a Celtic king born of deceit and adultery, grew to become one of the most famous rulers of Britain. He was a warrior, a knight and a king who killed giants, witches and monsters and led a band of heroes on many daring adventures. He is known for his Knights of the Round Table and for uniting the peoples of his land. Even though his end was tragic, he is still known and celebrated all over the world today. His story is painted on the halls of the British Parliament.
Arthur's story begins with Uther Pendragon, his father. Pendragon is smitten by Igraine, the wife of the Duke of Cornwall. Disguising himself as Igraine's husband he sneaks into her bed and she conceives Arthur. Merlin the wizard raises Arthur away from his parents. It is Merlin who had designed for Arthur's father Uther a great Round Table at which 150 knights could sit. Upon Uther's death, the knights do not know who should take his place. Merlin tells them that whoever could draw a mysterious sword out of a stone should be the next king. Many try but all fail. Then one day Arthur, who is attending his foster brother Sir Kay, is sent to find a sword to replace his brother's broken one. He comes upon the magical sword Excalibur in the stone and, not knowing the prophecy, drew it out. Thus, he is proclaimed the new king.
Arthur unites Britain and drives off the invading Saxons. He becomes a benevolent and well-loved king. His reign is known for its heroic deeds and chivalric romance. In fact the name of his castle, Camelot, has come to signify a golden age. The greatest quest of Arthur and his Knights is the quest for the mythical Holy Grail, the cup from which Jesus drank at the Last Supper. While King Arthur is never to find the Holy Grail himself, his knight Sir Galahad does because of his purity of heart.
King Arthur marries Guinevere, daughter of the King of Scotland. Merlin tries to warn him against the marriage because Guinevere is in love with Sir Lancelot, one of Arthur's knights. When Arthur discovers that his wife and Sir Lancelot are having an affair, Sir Lancelot flees for France and Arthur pursues him. In his absence, Arthur's nephew Mordred seizes power. Arthur returns to Britain and a terrible battle ensures, during which most of his knights die and he is grievously wounded. He has Excalibur thrown back into the lake, and boards a boat for the magical Isle of Avalon. Here, he hopes to be cured of his wounds so that he might return to lead his people again. For this reason, Arthur is called "the once and future king."