In 1975 Valiant was struggling as its sales figures fell, and it was in danger of being cancelled. John Wagner was asked to take over as editor and reinvigorate the title with better, more hard-hitting stories. At the time, Wagner was the editor of a girls' comic, but he had previously helped to set up and launch Battle, a boys' war comic. One-Eyed Jack was one of the new stories Wagner introduced to Valiant, and he wrote all of the episodes which appeared in Valiant. It was inspired by the 1971 filmDirty Harry and other police films and television shows. The first episode appeared in the 20 December 1975 issue, and it immediately became the most popular story in the comic. Wagner attributes this in part to Cooper's artwork. In his introduction to the 2017 trade paperback collection, he wrote: "The impact of the story was in huge measure posted by the slick, superb artwork of John Cooper... The characters and the city came to life." The lead character was Detective Jack McBane, who lost his left eye when he was shot by a robber in the first episode. After ten years of doing police work "by the book," McBane became ruthless and willing to do whatever it took to beat the criminals he encountered. Each episode was three or four pages long, and usually contained a complete story, although there were some two- or three-episode stories. The weekly episodes were in black and white, but there was a full-colour episode in the 1978 Valiant Annual. After ten months, Valiant was merged into Battle on 23 October 1976, and Wagner's involvement with the strip ended. It continued to appear in Battle, written by Gerry Finley-Day and others, and John Cooper continued to provide the art. McBane left the police force and became a spy for the US military. After the strip ended, it was reprinted in Eagle comic, starting in July 1983. Some episodes were also reprinted in 2000 AD annuals. In 2017 all of the Valiant episodes were collected in a graphic novel by Rebellion's Treasury of British Comics imprint.
Inspiration for ''Judge Dredd''
In 1977, Wagner went on to create the strip Judge Dredd for 2000 AD. In a 1995 interview he said: "When Pat was putting together 2000 AD, we realised from the success of "One-Eyed Jack" this was the kind of story the paper should have – a really hard, tough cop." In 2017 he wrote: "The lessons I learned from One-Eyed Jack played no little part in the creation of Judge Dredd".