The First Doctor met John's elder siblings Richard the Lionheart and Princess Joanna in Palestine during the Crusade (TV: The Crusade) in the 1190s. (PROSE: Doctor Who and the Crusaders) During that encounter, Richard complained to the Doctor of how John planned to usurp Richard's crown and traded with his enemy, King Philip of France. (TV: The Crusade)
He became King of England upon the death of his brother Richard the Lionheart in 1199. He was most famous for losing the Duchy of Normandy to Philip II of France, and for the revolt of the barons, which led to the signing of the Magna Carta in 1215. (PROSE: A History of Humankind)
While the real King John was in London taking the Crusader's Oath on 4 March 1215, the android Kamelion was being used in a plot by the Master to sabotage Earth history by preventing King John's signing of the Magna Carta, an event pivotal to the development of parliamentary democracy on that planet. The plot was foiled by the intervention of the Fifth Doctor.
On one occasion, the Third Doctor briefly encountered a peasant from John's England who had been sent to London in the 1970s by a time eddy. The peasant told them that his king was Richard but John ruled England while his brother was in the Holy Land. (TV: Invasion of the Dinosaurs)
Behind the scenes
In 1216, whilst eluding rebel forces, John sent his baggage train across the square-mouthed estuary on the northwest margin of East Anglia, only to have the British Crown Jewels it carried accidentally dropped and sunk in its waters. Tegan Jovanka's foreknowledge of this event was summed up in her assessment of John as "the one who lost something in the Wash."
He was played by John Duttine in The Devil's Crown.