King Arthur was a fabled British leader and a prominent figure in Britain's legendary history, said in many medieval tales and chronicles to have taken the mantle of rulership over Britain and defended his land against Saxon invaders following the withdrawal of Rome. Arthur's story includes considerable elements of legend and folklore, and his very existence is debated and has become a point of fierce controversy among modern historians. The scarce historical background to Arthur is found scattered across various works including those of "Nennius" and Gildas and in the Annales Cambriae. The legendary Arthur was developed as a figure of international interest largely through the 12th century pseudo-history of Geoffrey of Monmouth, although Welsh and Breton stories and poems were circulating before he wrote. Chrétien de Troyes began the literary tradition of Arthurian romance, which subsequently became one of the principal themes of medieval literature. Medieval Arthurian writing reached its conclusion in Thomas Mallory's comprehensive Morte D'Arthur, published in 1485. Modern interest in Arthur was revived by Alfred Lord Tennyson in Idylls of the King, and in the paintings of the Pre-Raphaelites. Key modern reworkings of the Arthurian legends include Richard Wagner's opera Parsifal, Mark Twain's satiric A Connecticut Yankee in King Arthur's Court, and T. H. White's The Once and Future King. Despite the controversy over the existence of a single historical Arthur, he was recently ranked as one of the 100 Greatest Britons of all time.

The central themes of the Arthurian cycle vary depending on which texts are examined. However, they include the establishment of Arthur as king through the sword in the stone episode, the advice of the wizard Merlin, the establishment of the fellowship of knights known as the Round Table and its associated code of chivalry, the defence of Britain against the Saxons, numerous magical adventures associated with particular knights – notably Kay, Gawain, Lancelot, Percival and Galahad – the enmity of Arthur's half-sister Morgan le Fay, the quest for the Holy Grail, the adultery of Lancelot and Queen Guinevere, the final battle with Mordred, and the legend of Arthur's future return. The magical sword Excalibur, the castle Camelot and the Lady of the Lake also play pivotal roles.

King Arthur's Disasters is an animated series that airs on CITV on ITV1 in the United Kingdom, Cartoon Network in Latin America, France and Portugal, ABC Australia and Toon Disney in both Italy and Spain. As of 2006 Nicktoons UK began airing repeats of series 1. Created by Paul Parkes, the series depicts the (often anachronistic) attempts by King Arthur, assisted by the wizard Merlin, to woo the beautiful but self-obsessed Princess Guinevere. Due to the popularity of the show, it was picked up for a second series which began/ transmission on CITV on ITV1 in the UK on the 6th November 2006.

When the real King Arthur and his knights are captured by Morgana, Merlin casts a spell to bring an american football team called The Knights lead by Arthur King to the past to help free the real king and stop Morgana's evil plans by collect magical keys. There was one key for each knight and one for King Arthur. Written by Rocketeevee