Origin
During the 1970s Detective Inspector Jack Regan was a senior officer in the Metropolitan Police’s armed Flying Squad, a.k.a. the Sweeney, the nickname originating from Sweeney Todd, the Cockney ryhming slang for Flying Squad.
Creation
Created by Ian Kennedy Marting and played by John Thaw, Regan was introduced to viewers in a one-off play on Armchair Theatre in 1974 named after the character, with a series already commissioned to follow before this pilot was made. The Sweeney began a year later, in January 1975, and ran for four series, with tie-in novels and annuals, plus two theatrical movies, before ending with Regan resigning in anger, having been locked up for corruption and then exonerated. However, the first movie, filmed between series 3 and 4, is apparently set a few years in the future, suggesting Regan changed his mind and returned to the force. The character also turned up in a cameo in a Professionals novel, a tie-in to another popular ITV drama.