Trivia: Such was the popularity of Doctor Who in Britain in the mid-1960s that even the Beatles wanted to make an appearance in the show. So a scene was written into "The Chase" to allow them to appear. The idea had been devised of including a scene on the Time and Space Visualiser depicting a Beatles fiftieth-anniversary concert in 2015, with the Fab Four dressed up as old men. John, Paul, George, and Ringo themselves were interested in the proposition, but it was vetoed by their manager, Brian Epstein. It was then thought that an appearance by the Beatles on Top of the Pops might be used instead, but no such footage was available. Fortunately, the Beatles were scheduled to perform "Ticket to Ride" at Riverside Studios in Hammersmith on April 10th, 1965, and that footage was used instead.
Trivia: This Doctor Who story was originally scripted and produced as a four-episode story, but, just two weeks before transmission, upon viewing the story, co-creators Sydney Newman and Donald Wilson felt that the final two episodes (Episode 3, 'Crisis'; and Episode 4, 'The Urge to Live') should be combined into a single episode. The new 'condensed' episode incorporated the opening titles of 'Crisis' with the closing credits of 'The Urge to Live'.
Trivia: The first episode of the Doctor Who story "The Crusades" was called "The Lion" (a reference to King Richard I, "The Lionheart") and was first broadcast on March 27, 1965. This episode was really bad. The only surviving copy was returned to the BBC Archives in January 1999, from a film collector in New Zealand, who had bought it at a car boot sale for $5.00NZ (about $3US). The vendor of this episode of Doctor Who had recovered it several years before from a landfill site in Wellington, New Zealand, where TV NZ had dumped it when clearing out its archives.
Trivia: The plot of this Doctor Who story was adapted and remade by Hammer Films into a full blown cinema release, Dalek Invasion Earth 2150AD, which was released in 1966 and starred Peter Cushing as a human actually named "Doctor Who." The major change in the plot was to redate the story from 2164AD to 2150AD.