BBC1 premieres the 31st episode of Terry Nation’s science fiction series Blake’s 7. 
BBC1 premieres the 31st episode of Terry Nation’s science fiction series Blake’s 7.
BBC1 premieres the 32nd episode of Terry Nation’s science fiction series Blake’s 7. Colin Baker (Doctor Who) and Valentine Dyall guest star.
BBC1 premieres the 33nd episode of Terry Nation’s science fiction series Blake’s 7.
BBC1 premieres the 34th episode of Terry Nation’s science fiction series Blake’s 7.
BBC1 premieres the 35th episode of Terry Nation’s science fiction series Blake’s 7. This episode, written by fantasy novelist Tanith Lee, is unique in that it features only the regular cast with no speaking guest stars.
BBC1 premieres the 36th episode of Terry Nation’s science fiction series Blake’s 7. This episode is written by novelist Trevor Hoyle, who has already penned two Blake’s 7 tie-in novelizations during the series’ first season.
BBC1 premieres the 37th episode of Terry Nation’s science fiction series Blake’s 7.
BBC1 premieres the 38th episode of Terry Nation’s science fiction series Blake’s 7.
BBC1 premieres the 39th episode of Terry Nation’s science fiction series Blake’s 7, ending the third season and seeing out series regular Jan Chappell (Cally) and the Liberator. This is the last script written for the series by Terry Nation, as he has decided to try his fortunes as a writer and producer in Hollywood, and is intended to be the series finale. When broadcast on the BBC, a voice-over on the end credits informs viewers that Blake’s 7 will return in 1981 – something that even the cast and crew aren’t aware of until then. Gareth Thomas guest stars as Blake.
BBC1 premieres the 40th episode of Terry Nation’s science fiction series Blake’s 7, the first episode of the series’ fourth season. Due to a last-minute pickup by the BBC, the series has to reboot from this point with a new ship, new sets, costumes, props, and a new direction decided on without significant input from series creator Terry Nation. Jan Chappell provides a voice-over for Cally, who doesn’t appear in person. Glynis Barber is introduced as new series regular Soolin.
BBC1 premieres the 41st episode of Terry Nation’s science fiction series Blake’s 7, concluding the opening two-episode story of Avon and crew securing a new ship and base for themselves.
BBC1 premieres the 42nd episode of Terry Nation’s science fiction series Blake’s 7. Jacqueline Pearce returns as Servalan, attempting to hide her identity as Federation Commissioner Sleer. (Sleer was devised as a new character during pre-production for the fourth season when it appeared that Pearce would not return to the series; upon the actress’ return, Sleer is rewritten as Servalan’s alias after her fall from the presidency.)
BBC1 premieres the 43rd episode of Terry Nation’s science fiction series Blake’s 7. Barbara Shelley guest stars.
BBC1 premieres the 44th episode of Terry Nation’s science fiction series Blake’s 7. Jacqueline Pearce and Kevin Stoney guest star.
BBC1 premieres the 45th episode of Terry Nation’s science fiction series Blake’s 7. Lynda Bellingham (All Creatures Great & Small) guest stars.
BBC1 premieres the 46th episode of Terry Nation’s science fiction series Blake’s 7. Richard Hurndall guest stars; Doctor Who producer John Nathan-Turner is so impressed with Hurndall’s “Hartnell-esque” performance that he casts the actor in the late William Hartnell’s role of the first Doctor in the 20th anniversary special The Five Doctors in 1983.
BBC1 premieres the 47th episode of Terry Nation’s science fiction series Blake’s 7. Jacqueline Pearce and Stratford Johns guest star.
BBC1 premieres the 48th episode of Terry Nation’s science fiction series Blake’s 7. Jacqueline Pearce guest stars.
BBC1 premieres the 49th episode of Terry Nation’s science fiction series Blake’s 7. Roy Kinnear guest stars.
BBC1 premieres the 60th episode of Terry Nation’s science fiction series Blake’s 7. John Savident guest stars.
BBC1 premieres the 60th episode of Terry Nation’s science fiction series Blake’s 7. This is Jacqueline Pearce’s final appearance as Servalan in the series.
BBC1 premieres the 52nd and final episode of Terry Nation’s science fiction series Blake’s 7. By all accounts one of the most memorable and unsettling television finales ever, the final episode hints strongly that evil has triumphed, and some viewers already experiencing depression as the Christmas holiday closes in are extremely disturbed by the series’ conclusion. Gareth Thomas guest stars as Blake, bringing the series full circle.