It is said that Leslie Charteris' seminal anti-hero, The Saint, was inspired by the literary exploits of a gentleman thief-turned-private detective named Michael Lanyard, otherwise known as The Lone Wolf. I find this amusing, as Wolf wasn't able to make as smooth a transition to the small screen as Simon Templar would a few years later.
Both characters appeared in films, books, and on radio. However, The Saint became a pop culture icon in the 60's, thanks to ITC's adaptation of the character, starring Roger Moore. Louis Hayward was cast as Lanyard in 1954, but the Lone Wolf lasted one season, largely because Hayward looked more like just another detective, not a reformed criminal trying to make amends. In short, a generic hero.
Keep an eye open for a pre-Star Trek DeForest Kelley, who made a few appearances in this series, in the episode, "The Murder Story":
Oddly, Moonstone Press adapted and rebooted Lone Wolf for comics some years ago. Why a reboot? Because the Wolf in this case was a woman. Don't ask.