The TARDIS brings the Doctor, Vicki and Steven to 1066 England, just prior to the Battle of Hastings. There they discover that the Meddling Monk, a time-travelling member of the Doctor's own race, has been interfering with history. The Monk is attempting to use advanced technology to change the outcome of the Battle, wielding modern weaponry to defeat William the Conqueror, and hence irrevocably alter Earth's future.

By early March 1965, it was clear that Serial S -- intended to conclude Doctor Who's second season -- would be something of a crisis point. Producer Verity Lambert had decided to leave the show, and would be winding down her involvement in it by that time. It appeared that William Russell would be departing from Doctor Who as of the preceding adventure, The Chase, necessitating the introduction of a new companion in its final episode who would then need further development in Serial S. Neither Jacqueline Hill nor Maureen O'Brien had yet to confirm whether they would be continuing on beyond The Chase. And to muddy the waters further, no regular Doctor Who writer was available; Serial S would have to be inexpensive to offset the high budget allocated to The Chase; and William Hartnell's agent had convinced Lambert to give the star another week's holiday, meaning that the Doctor would have to be absent from the story's second episode.

With all of this in mind, on March 11th Lambert wrote to Head of Serials Donald Wilson seeking permission to commission story editor Dennis Spooner to write the scripts, a practise very much discouraged by the BBC. Spooner had already written two Doctor Who adventures, most recently The Romans. On March 15th, Wilson acknowledged that the Serial S situation was unusual, and agreed to Lambert's request. As it happened, Spooner shortly thereafter decided not to renew his six-month contract; therefore, his replacement, Donald Tosh, would begin receiving the story editor's credit as of this story, despite the fact that Spooner would continue to work on Doctor Who in that capacity well into the summer months.

In composing his storyline, Spooner sought to shift Doctor Who away from the “straight” historicals which had characterised the programme to date, and instead involve more science-fiction elements in adventures set in the Earth's past. By so doing, Spooner effectively pioneered the “pseudohistorical” genre which would soon supplant regular historicals in the Doctor Who canon. In naming his characters, Spooner sought inspiration from actual contemporaneous figures. These included Edith (named for one of King Harold's sisters), Ulf (an earl and uncle to Harold), Sven (from Harold's brother Sweyn, by which spelling the character was sometimes referred), and Wulnoth (derived from Harold's grandfather, Wulfnoth). Late in the day -- by which time it was known that Hill would be leaving Doctor Who and O'Brien staying -- Spooner's scripts gained the working title of “The Monk”.

The director assigned to “The Monk” was Douglas Camfield, who had recently helmed The Crusade. A minimal amount of filming was undertaken at the Ealing Television Film Studios on May 10th. This day also saw Camfield oversee some sequences for The Chase involving the departure of Ian and Barbara; four days earlier, Camfield had accompanied Russell, Hill and a stills photographer on a tour of London landmarks for shots to be included in the same story. During the following week, Peter Purves accepted the role of new companion Steven Taylor; Serial S would be his first full adventure.

By the time episode one, The Watcher, was taped on June 11th, the serial's title had been fixed as The Time Meddler. Also around this time, Lambert's successor, John Wiles, began trailing the producer and would effectively take over the day-to-day duties of the position by the end of recording on the serial. Hartnell, upset by the many changes affecting Doctor Who around this time, reacted disagreeably, play-acting at throwing tantrums during rehearsals to try to intimidate Wiles and Tosh.

As usual, The Time Meddler was taped on consecutive Fridays. However, the decision was made to shift the programme out of its usual studio home of Riverside 1 and back to BBC Television Centre, which had been used sporadically during the first production block and again recently for The Space Museum. The Watcher was recorded in TC4; it was during this episode that O'Brien mispronounced the scripted explanation of the TARDIS acronym -- Time And Relative Dimension In Space, as given in the very first Doctor Who story, 100,000 BC -- as the pluralised Time And Relative Dimensions In Space. This error would be inadvertently retained throughout much of the rest of the programme's history.

Hartnell was absent from the recording of The Meddling Monk, which took place in TC3. He had prerecorded some lines for the Doctor's off-camera appearances the previous week. The programme's star was back for the next installment, which saw production return to TC4. This was also the venue for the final episode, Checkmate, on July 2nd. The following day, part one of The Time Meddler was broadcast, albeit in an unusually late 6.55pm timeslot because of an extended edition of the sports programme Grandstand. The transmission of Checkmate on July 24th brought Season Two of Doctor Who to a close.

• Doctor Who: The Handbook: The First Doctor by David J Howe, Mark Stammers and Stephen James Walker (1994), Virgin Publishing, ISBN 0 426 20430 1.
• Doctor Who: The Sixties by David J Howe, Mark Stammers and Stephen James Walker (1992), Virgin Publishing, ISBN 1 85227 420 4.
• Doctor Who Magazine #307, 22nd August 2001, “Archive: The Time Meddler” by Andrew Pixley, Panini Publishing Ltd.
• Doctor Who Magazine Special Edition #7, 12th May 2004, “I'm Into Something Good” by Andrew Pixley, Panini Publishing Ltd.