with 211 episodes premiered on August 26, 1991

with 42 episodes premiered on November 23, 1963

The season introduces William Hartnell as the First Doctor, an alien who travels through time and space in his TARDIS, which appears to be a British police box on the outside. Carole Ann Ford is also… see more

with 39 episodes premiered on October 31, 1964

Milestones this season included not one but two encore appearances by the Daleks; the departure of the original three companions, Susan Foreman, Barbara Wright and Ian Chesterton; and the first appea… see more

with 45 episodes premiered on September 11, 1965

At twelve episodes, The Daleks' Master Plan was the longest story in the show's history until superseded by the fourteen-episode The Trial of a Time Lord in 1986. The season also had the greatest num… see more

with 43 episodes premiered on September 10, 1966

This season was a season of major changes for Doctor Who, including some that have influenced the series and franchise ever since. Most notably, season 4 saw William Hartnell's First Doctor hand off … see more

with 40 episodes premiered on September 2, 1967

No complete stories from the season were known to have survived until the early-1990s when archivists recovered a complete version of The Tomb of the Cybermen. A second complete story, The Enemy of t… see more

with 44 episodes premiered on August 10, 1968

This season featured the first ever UNIT story, The Invasion, which showcased the return of Brigadier Lethbridge-Stewart. It also featured the first official appearance of Time Lords and the as yet u… see more

with 25 episodes premiered on January 3, 1970

It was the first series produced and broadcast in colour and the first set entirely in one time period and almost entirely on Earth (the latter of these factors would later be repeated for Season 26 … see more

with 25 episodes premiered on January 2, 1971

As of 2017, season 8 remains notable for being the season with the most number of regular characters. Not only did it see a new companion in the form of Jo Grant, but it featured a regular enemy — Th… see more

with 26 episodes premiered on January 1, 1972

It was noted for being the beginning of the end of the Doctor's exile on Earth, with the Doctor's TARDIS still under the control of the Time Lords (The Mutants) and restricted freedom (The Curse of P… see more

with 26 episodes premiered on December 30, 1972

William Hartnell returned in a cameo as the First Doctor and Patrick Troughton in a more substantial role as the Second Doctor in The Three Doctors. This story marked the end of the Doctor's exile on… see more

with 26 episodes premiered on December 15, 1973

It was Jon Pertwee's final season as the Doctor and included, very briefly, the first appearance of Tom Baker as the Fourth Doctor. The Time Warrior, the season opener, introduced Sarah Jane Smith, w… see more

with 20 episodes premiered on December 28, 1974

All the stories in this season were interconnected, several forming a loose story arc relating to Space Station Nerva. The Cybermen returned to the series for the first time since The Invasion. Genes… see more

with 26 episodes premiered on August 30, 1975

It was during this season that the Doctor cut ties to UNIT (after Terror of the Zygons, the Brigadier would not appear again until Mawdryn Undead in 1983, and The Seeds of Doom marked the last occasi… see more

with 26 episodes premiered on September 4, 1976

The season is notable for the departure of Sarah Jane Smith in The Hand of Fear and for The Deadly Assassin, a story set entirely on Gallifrey which expounded greatly upon the culture and history of … see more

with 26 episodes premiered on September 3, 1977

This season introduced K9 to the series and saw the departure of Leela. It was originally intended to include Terrance Dicks' story The Vampire Mutations but, due to a major BBC production of Dracula… see more

with 26 episodes premiered on September 2, 1978

This season saw the introduction of the Black and White Guardians as well as the companion Romana, who became only the second female Time Lord companion since Susan. This season is sometimes colloqui… see more

with 20 episodes premiered on September 1, 1979

It consisted of five stories, plus the incomplete Shada, unfinished as a result of an industrial strike. Lalla Ward joined as Romana II, and the season is notable for the involvement of Douglas Adams… see more

with 28 episodes premiered on August 30, 1980

The season featured a story arc involving E-Space and the return of the Master who had stolen a new body rather than regenerate. The stories were darker and more adult in tone than those during the G… see more

with 26 episodes premiered on January 4, 1982

Two milestones occurred in Earthshock. Firstly, the Cybermen returned, unannounced, for the first time since Revenge of the Cybermen in 1975 with a completely different design, with David Banks' firs… see more

with 22 episodes premiered on January 3, 1983

Structurally, the season retread season 18's formula of including a trilogy of stories bound together by an overarching theme. In this instance, the tripartite tale involved Turlough's attempts to ki… see more

with 24 episodes premiered on January 5, 1984

The Twin Dilemma, the first story with Colin Baker as the Sixth Doctor, aired last in the season. This season saw the departure of companions Tegan, Turlough and Kamelion and introduced Peri. Most ep… see more

with 13 episodes premiered on January 5, 1985

With this season the BBC experimented with the format of the series, reducing the number of episodes to thirteen, but making each episode forty-five minutes long. The experiment did not result in imp… see more

with 14 episodes premiered on September 6, 1986

This season had a unique format, never again repeated in the show. Doctor Who had returned to production after a near-cancellation and an eighteen-month production hiatus. For the first time, a seaso… see more

with 14 episodes premiered on September 7, 1987

Unlike season 23, there was no overall story arc, and the episode allotment - two four-episode stories, two three-episode stories - would be retained for the remainder of the original series. Notably… see more

with 14 episodes premiered on October 5, 1988

As the silver anniversary season, it included several stories noting the milestone: Remembrance of the Daleks, which featured the final "classic series" appearance of the Daleks and Davros and which … see more

with 14 episodes premiered on September 6, 1989

It was the final season of the "classic" series. Unusually for a Doctor Who season, aside from some scenes in Survival, all the stories took place on Earth. Apart from Battlefield, the stories follow… see more