Ian Chesterton is a fictional character in the British science fiction television series Doctor Who and a companion of the First Doctor. He was played in the series by William Russell, and was one of the members of the programme's first regular cast, appearing in the bulk of the first two seasons from 1963 to 1965. In a film adaptation of one of the serials, Dr. Who and the Daleks (1965), he was played by Roy Castle, but with a very different personality and backstory. Ian appeared in 16 stories (77 episodes). Appearances Ian Chesterton is a science teacher at the Coal Hill School and works with Barbara Wright, a history teacher. One of their students, Susan Foreman, the granddaughter of the Doctor, shows unusually advanced knowledge of science and history. Attempting to solve the mystery of this "unearthly child," Ian and Barbara follow Susan back home to a junkyard, where they hear her voice coming from what appears to be a police box. When they investigate further, they discover that the police box exterior hides the much larger interior of a time machine known as the TARDIS, and are whisked away on an adventure in time and space with the Doctor and Susan. Ian provides the series with an action-orientated figure, able to perform the physical tasks that the elderly Doctor cannot. The Doctor rarely calls him by his first name (Ian) as the others do but rather by his surname, Chesterton. There was also a small number of instances where William Hartnell mistakingly calls him Chesterfield. His concern, above all, is for the safety of the TARDIS crew, and in the early stories he often takes issue with the Doctor's habit of placing the group in harm's way just to satisfy his own curiosity. The chemistry between Barbara and himself is also evident, although the nature of their relationship is never made explicit in the television series, and their eventual marriage is only revealed forty-five years later. Ian shows a breadth of skills throughout his tenure with the Doctor. He manages to create fire (An Unearthly Child), rides a horse, knows how to fight with swords (The Romans) and is knowledgeable about pressure points that can paralyse an opponent (The Aztecs). He is also fiercely protective of Barbara, going on a lone mission to rescue her from Saracens in The Crusade. In that story, he is also knighted