Doctor Who first appeared on BBC TV at 17:16:20 GMT on Saturday, 23 November 1963; this was eighty seconds later than the scheduled programme time, because of the assassination of John F. Kennedy the previous day.[5][6] It was to be a regular weekly programme, each episode 25 minutes of transmission length. Discussions and plans for the programme had been in progress for a year. The head of drama Sydney Newman was mainly responsible for developing the programme, with the first format document for the series being written by Newman along with the head of the script department (later head of serials) Donald Wilson and staff writer C. E. Webber. Writer Anthony Coburn, story editor David Whitaker and initial producer Verity Lambert also heavily contributed to the development of the series.
The programme was originally intended to appeal to a family audience[8] as an educational programme using time travel as a means to explore scientific ideas and famous moments in history. On 31 July 1963, Whitaker commissioned Terry Nation to write a story under the title The Mutants. As originally written, the Daleks and Thals were the victims of an alien neutron bomb attack but Nation later dropped the aliens and made the Daleks the aggressors. When the script was presented to Newman and Wilson it was immediately rejected as the programme was not permitted to contain any "bug-eyed monsters". According to producer Verity Lambert; "We didn't have a lot of choice — we only had the Dalek serial to go ... We had a bit of a crisis of confidence because Donald [Wilson] was so adamant that we shouldn't make it. Had we had anything else ready we would have made that." Nation's script became the second Doctor Who serial – The Daleks (also known as The Mutants). The serial introduced the eponymous aliens that would become the series' most popular monsters, and was responsible for the BBC's first merchandising boom.
The BBC drama department's serials division produced the programme for 26 seasons, broadcast on BBC 1. Due to his increasingly poor health, the first actor to play the Doctor, William Hartnell, was replaced by the younger Patrick Troughton in 1966. In 1970 Jon Pertwee replaced Troughton and the series at that point moved from black and white to colour. In 1974 Tom Baker was cast as the Doctor. His eccentric style of dress and quirky personality became hugely popular, with viewing figures for the show returning to a level not seen since the height of "Dalekmania" a decade earlier. In 1981, after a record seven years in the role, Baker was replaced by Peter Davison, at 29 by far the youngest actor to be cast as the character in the series' first run, and in 1984 Colin Baker replaced Davison. In 1985 the channel's controller Michael Grade attempted to cancel the series, but this became an 18-month hiatus instead. He also had Colin Baker removed from the starring role in 1986. The role was recast with Sylvester McCoy, but falling viewing numbers, a decline in the public perception of the show and a less-prominent transmission slot saw production ended in 1989 by Peter Cregeen, the BBC's new head of series. Although it was effectively cancelled with the decision not to commission a planned 27th season, which would have been broadcast in 1990, the BBC repeatedly affirmed, over several years, that the series would return.
While in-house production had ceased, the BBC hoped to find an independent production company to relaunch the show. Philip Segal, a British expatriate who worked for Columbia Pictures' television arm in the United States, had approached the BBC about such a venture as early as July 1989, while the 26th season was still in production. Segal's negotiations eventually led to a Doctor Who television film, broadcast on the Fox Network in 1996 as an international co-production between Fox, Universal Pictures, the BBC and BBC Worldwide. Starring Paul McGann as the Doctor, the film was successful in the UK (with 9.1 million viewers), but was less so in the United States and did not lead to a series.
Licensed media such as novels and audio plays provided new stories, but as a television programme Doctor Who remained dormant until 2003. In September of that year, BBC Television announced the in-house production of a new series after several years of attempts by BBC Worldwide to find backing for a feature film version. The executive producers of the new incarnation of the series were writer Russell T Davies and BBC Cymru Wales head of drama Julie Gardner.
Starring Christopher Eccleston as the Doctor, Doctor Who finally returned with the episode "Rose" on BBC One on 26 March 2005. Eccleston left after one series and was replaced by David Tennant. There have since been eleven further series in 2006–2008, 2010–2015, 2017–2018, 2020, and Christmas/New Year's Day specials every year since 2005, with the exception of 2018. No full series was broadcast in 2009, although four additional specials starring Tennant were made. Davies left the show in 2010 after the end of series 4 and the David Tennant specials were completed. Steven Moffat, a writer under Davies, was announced as his successor, along with Matt Smith as the new Doctor. Smith decided to leave the role of the Doctor in the 50th anniversary year. He was replaced by Peter Capaldi.
In January 2016, Moffat announced that he would step down after the 2017 finale, to be replaced by Chris Chibnall in 2018. The tenth series debuted in April 2017, with a Christmas special preceding it in 2016. Jodie Whittaker was announced as the first female Doctor, and has appeared in two series and is scheduled to reprise her role in a third, shorter series.
The 2005 version of Doctor Who is a direct plot continuation of the original 1963–1989 series and the 1996 telefilm. This is similar to the 1988 continuation of Mission Impossible, but differs from most other series relaunches which have either been reboots (for example, Battlestar Galactica and Bionic Woman) or set in the same universe as the original but in a different time period and with different characters (for example, Star Trek: The Next Generation and spin-offs).