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 very 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).

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. 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.[1]

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 by King Richard I of England as "Sir Ian of Jaffa". After many travels, Ian and Barbara eventually use a Dalek time machine to go home, two years after their disappearance.

The character of Ian was intended by the production team to return for a guest appearance in the 1983 Doctor Who story Mawdryn Undead, but this plan fell through when Russell proved to be unavailable. The script was modified to instead feature Alistair Lethbridge-Stewart as the story's schoolteacher character. However, in 1999 Russell did return to the part for the BBC Worldwide video release of The Crusade, two of the four episodes of which are missing from the archives. Russell provided linking narration between the existing episodes in character as an aged Ian Chesterton reminiscing about the events of the story.

Ian was mentioned in Death of the Doctor, a two-part story in the fourth series of The Sarah Jane Adventures transmitted in October 2010. Sarah Jane Smith states that Ian and Barbara have married, become professors, live in Cambridge, and are said not to have aged since the 1960s. In the 50th Anniversary Special "The Day of the Doctor", the sign for Coal Hill Secondary School in the opening shot labels the Chairman of the Governors as I. Chesterton. Coal Hill teacher and companion of the Doctor Clara Oswald does not notice his photograph and name on the bulletin board in UNIT's Black Archive, in the same episode, when pausing over an adjacent photograph of Susan.

The novelisation of The Daleks by David Whitaker is written in first person from Ian Chesterton's perspective, and changes his initial meeting with the Doctor, Susan, and Barbara to a car accident involving the two ladies. The TARDIS then arrives on Skaro rather than prehistoric earth, with the story continuing much as the TV serial from then on. In this version, Ian is a chemist returning from an unsuccessful job interview, but his character is otherwise unchanged.

In the film adaptation Dr. Who and the Daleks, Ian Chesterton is the boyfriend of Barbara, granddaughter of Dr. Who. Rather than the man of action from the TV series, this Ian is a clumsy idiot who manages to survive more through luck than any degree of competence. In Daleks - Invasion Earth 2150 AD, the character of Ian is replaced by Tom Campbell, who performs much the same role as Ian in The Dalek Invasion of Earth.

Since 1994, the character has also appeared in various novels from Virgin Publishing and BBC Books, set between televised adventures during his particular era of the programme. One BBC Books novel, The Face of the Enemy by David A. McIntee (1998), picks up the story of Ian and Barbara, now married to each other, in the early 1970s, the two of them collaborating with the Doctor's colleagues at UNIT and his enemy the Master when Ian is hired as the Third Doctor's temporary replacement while the Doctor is taking a trip away from Earth. In this book, they have a young son named John. Many of the novels mention a 1980s pop star named Johnny Chester or Johnny Chess, intended to be the same character. Chess is idolised by the Seventh Doctor's companion Ace and has apparently been romantically involved with the Fifth Doctor's companion Tegan.

In issue #456 of The Doctor Who Magazine, the eleventh Doctor investigates strange psychic metal and finds Ian and Barbara inside, who believe they are teaching several classes for a wide range of students. In the following issues the two help the Doctor investigate a conspiracy that stretches through the years they knew 'their' Doctor and beyond. At the end, Ian and Barbara are married. [2]

Biography from the wikipedia article, licensed under CC-BY-SA