Derrick Sherwin worked on Doctor Who in many capacities, writing scripts, producing the series for the transition between the second and third Doctor, and even appearing in one scene, playing a Car Park Attendant in the 1970 story Spearhead from Space. His most lasting legacy was creating the United Nations Intelligence Taskforce or UNIT for the 1968 story The Invasion. UNIT, helmed by Brigadier Lethbridge-Stewart, was an essential component for the Third Doctor's tenure, with its influence reaching as far as the Twelfth Doctor.
Sherwin was born in 1936 in the Buckinghamshire town of High Wycombe, just west of London. His early work was in the theatre, but he quickly moved into television appearing in the 1958 show Duty Bound. Over the next ten years, he had a steady series of small roles appearing in dramas such as Here Lies Miss Sabry, The Edgar Wallace Mystery Theatre, United! and Armchair Theatre.
His first contact with Doctor Who came when he joined as Assistant Script Editor to help the incumbent Peter Bryant who was preparing to take over as producer. It was a baptism of fire as he was immediately charged with rescuing a number of scripts which were not ready for production. He told Doctor Who Magazine.
It was just before Christmas, and I was landed with a great pile of scripts that had to go into production immediately after the holiday break. The director had sent them back and said he wouldn’t do them. Pat Troughton had thrown a wobbly – they really were appalling! That set the pattern for the first three months. It was a real baptism of fire.He took over as Script Editor for the 1968 story The Dominators and later that year had the chance to write his own story from scratch. The result was The Invasion, the Cybermen story that set up the pattern for the series for much of the next five years. Sherwin felt the series had become too fantastical, with different monsters every week. He wanted to give the series a more grounded approach and saw as his inspiration the 1950's Quatermass stories. To help achieve that he took a character created for the story The Web of Fear, Colonel Lethbridge-Stewart, promoted him to Brigadier, and created UNIT around him.
I sat down and wrote a couple of pages about this special task force, specifically with members from all nations, which had been set up to investigate funny things happening in space or the possibility of UFO’s or whatever. It was basically an army intelligence unit with special powers and, on some occasions, special weapons.Sherwin took over of producer for the last Patrick Troughton story, The War Games and was responsible for casting the third Doctor Jon Pertwee and overseeing the series move from Black and White to Colour. He left the series after Spearhead in Space
He moved onto produce the series Paul Temple and later The Man Outside and Perils of Pendragon
In the 1980's, when Doctor Who was under threat of cancellation from the BBC he offered to buy the franchise from the BBC and produce it independently.
I wrote to Michael Grade and said ‘Look, obviously the BBC can’t afford to do this and doesn’t know where to go with it, so I will take it off your hands, produce it independently, finance it independently, and sell it back to you as a package’. He turned me down, saying that he’d got plans for the series. Then, when Grade left, I wrote to Peter Cregeen about it. So I offered to buy ‘Doctor Who’ out twice!Derrick Sherwin died on the 17th October after a long illness.