In the second series Doctor in Charge episode "Brotherly Hate", Richard O'Sullivan plays three roles: Lawrence Bingham, his identical brother Lionel (who impersonates Lawrence to persuade Sir Geoffrey to take Collier on as a surgeon), and, in the episode's final scene, Lawrence and Lionel's identical brother Leonard. All three appear on screen at once via the use of Green Screening (although the effects are rather obvious, as the colours don't quite match).
Ernest Clark plays both Sir Geoffrey Loftus and Captain Norman Loftus in Doctor at Sea, with both brothers appearing in the first and last episodes, "Sir John and Baby Doc" and "But It's So Much Nicer to Come Home". As in "Brotherly Hate", Clark's appearance as both characters on screen simultaneously is achieved through Green Screen techniques.
Creator Backlash: Doctor at the Top was regarded as a mistake by all who took part in it. When George Layton appeared on an episode of This Is Your Life honouring Bill Oddie, the latter referred to Doctor at the Top, for which Layton and Oddie had both been writers, as "Doctor Down the Drain".
Dawson Casting: In the first series of Doctor in the House, Michael Upton and Duncan Waring are supposed to be 18 or 19, Paul Collier, Huw Evans, and Dave Briddock about 20 or 21, and Dick Stuart-Clark about 23. However, they were played respectively by Barry Evans (26), Robin Nedwell (23), George Layton (26), Martin Shaw (24), Simon Cuff (25), and Geoffrey Davies (27). Evans and Nedwell were perhaps most successful at passing for younger (Evans in particular looked and sounded 17 or 18 years old for most of his acting career).
Executive Meddling: Doctor in the House was suddenly Cancelled by Barry Took, and the writers were only allowed to continue if they moved the series out of St. Swithin's. This led to the creation of Doctor at Large
Fake Nationality: Huw Evans was Welsh, but played by English actor Martin Shaw, while Danny Hooley was Irish, but played by English actor Jonathan Lynn. Both were frequently prone to Ooh, Me Accent's Slipping.
Hostility on the Set: Ernest Clark was terribly serious off-camera and would take great care to always have an immaculately folded copy of The Times. During one of the rehearsals for Doctor on the Go, John Kane borrowed his paper, then switched it for a different one and ripped it up in front of him. Clark was furious and raged at Kane, who then showed him his unharmed newspaper.
Throw It In!: Doctor at Large and Doctor in Charge had a total of 72 episodes between them, resulting in very tight shooting schedules. Many flubbed lines, wobbling sets, and visible boom mikes and cameras ended up in the finished series as a result (for example, in the Doctor at Large episode "Operation Loftus", Stuart-Clark talks about having to hide his stash of "illugal-legal booze"; Geoffrey Davies, Barry Evans, and George Layton struggle to suppress smiles at the mistake).
Uncredited Role: Linda Regan as a schoolgirl in the Doctor at Large episode, "Doctor Dish", and a girl at the dance in the Doctor in Charge episode, "The Taming of the Wolf".
Before Barry Evans, David Jason was wanted for the lead role of Michael Upton. Evans was seen as more "lovable", whereas Jason was viewed as a "knockabout comedian".
When Upton is asked how his St. Swithin's interview has gone in "Why Do You Want to Be a Doctor?", he was originally supposed to respond, "I really don't know". Frank Muir had come to watch the rehearsals and thought that being before the commercial break, the line had to be more positive, and so it became "I think I'm in".
The entire second series of Doctor in the House was co-written by Graeme Garden and Bill Oddie; Garden appeared in the episode "Doctor on the Box" as the presenter of the programme that has been filmed at St Swithin's - which turns out to be a viciously critical examination of the students' drunken antics at the taxpayers' expense.note Something with which Garden had firsthand experience, having studied medicine himself at Emmanuel College, Cambridge and King's College Hospital, London before going into comedy.
Before leaving the series, George Layton wrote a number of episodes of Doctor at Large and Doctor in Charge under the pseudonym Oliver Fry. His contributions to Doctor at Sea, Doctor on the Go, and Doctor at the Top were under his own name.
Jonathan Lynn wrote episodes of each series from Doctor at Large to Doctor on the Go, including the Doctor in Charge finale "Should Auld Acquaintance Be Forgot?" in which he reprised his role as Danny Hooley from Doctor in the House.
You Look Familiar: With over a hundred and fifty episodes and hundreds of speaking roles, the franchise inevitably cast some of the same actors in multiple roles. Just to name a few examples:
David Jason played a non-English-speaking patient in the Doctor in the House episode "What Seems to Be the Trouble?", a gardener and psychiatry patient in the Doctor at Large episode "Let's Start at the Beginning", and a Spaniard stowing away on the Begonia to get back home to Tenerife in the Doctor at Sea episode "Go Away, Stowaway!".
Nicholas Smith (Mr. Rumbold) played a morgue attendant in "Nice Bodywork - Lovely Finish" from Doctor in the House, and a patient trapped in the hospital during a suspected typhoid outbreak in the Doctor in Charge episode "The Epidemic".
Mollie Sugden (Mrs. Slocombe) played a white witch's patient in the Doctor at Large episode "It's All in the Mind", and later had a recurring role as Duncan Waring's mother in the first few episodes of Doctor in Charge.
Harold Bennett (Young Mr. Grace) played a similar sort of senile old man to his role on Are You Being Served?, first in a recurring role as elderly hospital board member Mr. Reeves starting with Doctor at Large, then as a visiting dignitary in the Doctor in Charge episode "The Merger".
Arthur Brough (Mr. Grainger) played a hotelier in "The Viva" from Doctor at Large, then showed up as a Health Ministry official in the Doctor in Charge episode "The Long, Long Night".
Christopher Biggins (alias Nero in I, Claudius) may hold the record with appearances in four series: an expectant father in Doctor at Large, a patient in Doctor in Charge, a ship's steward in Doctor at Sea, and a male nurse in Doctor on the Go.
After staying at the Gleneagles Hotel in Torquay while filming for Monty Python's Flying Circus and observing temperamental proprietor Donald Sinclair, John Cleese wrote the Doctor at Large episode "No Ill Feeling!", in which Michael Upton stays at a hotel run by a Henpecked Husband and his domineering wife. Doctor producer Humphrey Barclay (a Cambridge contemporary of Cleese's whose other production/direction credits include the Footlights Revue A Clump of Plinths and its radio series spinoff I'm Sorry I'll Read That Again) told Cleese he thought there might be a series in the hotel scenes. Four years later, the idea of an acerbic hotelier living in fear of his wife was indeed expanded into a series as Fawlty Towers.
The first six episodes of Doctor at Large are in black and white, as they were filmed during the ITV "colour strike" in 1970. The series goes to full colour for the seventh episode, "Change Your Partners".
Both of the franchise's lead actors, Barry Evans and Robin Nedwell, died under bizarre and tragic circumstances in their early 50s:
In 1997, the Leicestershire Police arrived at Evans' house to tell him his stolen car had been retrieved and found him dead of a head wound. An 18-year-old who had just ended his relationship with Evans was arrested for his murder but released without charge due to insufficient evidence; the high levels of alcohol in Evans' system led to suspicion that his death might have been an accident or suicide, and it remains an open case.
In 1999, Nedwell was staying at his parents' house after separating from his wife, and fell five feet off a ladder onto concrete while performing some work on the house's exterior. He was taken to hospital and had stitches put in a cut on his head, but the staff were not entirely happy with his condition. A few days later he went to his local doctor's surgery for further treatment and suffered a fatal heart attack in the waiting room.
