Trivia

With the death of Verity Lambert on November 22, 2007, he was the earliest surviving producer of Doctor Who (1963) and the only one to have produced the series during the 1960s. He produced only two serials: 1969's "The War Games" and 1970's "Spearhead from Space". These stories are notable as being Patrick Troughton's swansong and Jon Pertwee's debut respectively. The latter was also the first serial to have been produced in colour.

His script for The Invasion: Episode One (1968) is arguably one of the most influential in the series' history. In it he created the United Nations Intelligence Taskforce, which became a big part of Doctor Who (1963) for many years, especially throughout the Jon Pertwee era when the series was produced by his successor Barry Letts. To try and reinvigorate the series, which was suffering from low ratings at the end of the 1960s, Sherwin was responsible for the idea of exiling the Doctor to Earth, which he felt would make the series more relatable to the general audience. Terrance Dicks has also credited Sherwin with coming up with the idea of the Time Lords, another aspect of the series which has endured.

He began as a junior set designer and scenic artist in the theatre. He advanced from there to stage manager and lighting designer.

He set up an independent production company, SkyBoy, in 1974. In the early 80s, he ran the first ever computer animation company, Electronic Arts.

In 1967, after several years working as an actor and freelance writer, he was offered the job of assistant story editor on Doctor Who by the BBC Head of Serials Shaun Sutton.

He was in the Royal Air Force for two years in the 1950s as his National Service.