If you thought a brightly-colored TV show featuring a masked millionaire vigilante, his sidekick and a customized black car as his leading crimefighting tool might be a success, you’d be right. If you thought two of them would, you’d be wrong.

While 1966’s Batman – starring Adam West – became an unforgotten mainstream hit, its simultaneous sister series The Green Hornet didn’t reach the same heights. It was canceled after ending its run four episodes early on March 17, 1967, although it later achieved cult status.

Like Batman, The Green Hornet was based on a previously-extant character, and the show was created, run and narrated by William Dozier. He opened each episode with the introduction: “Another challenge for the Green Hornet, his aide Kato, and their rolling arsenal, the Black Beauty. On police records a wanted criminal, the Green Hornet is really Britt Reid, owner-publisher of the Daily Sentinel; his dual identity known only to his secretary, and to the district attorney. And now, to protect the rights and lives of decent citizens, rides The Green Hornet!”

Watch the ‘Green Hornet’ Opening

While Batman was played for laughs, actor Van Williams played the Hornet and Reid as a serious-minded social warrior. “I remember listening to it as a kid, and it was a very proper radio show,” Williams said in 1988. “Those characters just have an appeal… they’re heroes out there, doing a job that the cops can’t do. That’s the appeal of a vigilante.” But like many superhero type characters, Williams had a fatal flaw: he was becoming disillusioned with acting. Even though he described the Hornet as “the most sought-after role that year,” he’d had enough of shooting pilots that were never picked up. “I always kinda looked at it as a business, and I think that’s primarily the reason, when I was doing The Green Hornet, I decided to get out of it. Because it was not a good business!”

Dozier found himself at odds with his bosses at the ABC network from the outset. In fact, he’d been trying to secure the rights to the Lone Ranger, before having to settle for the Hornet – created by the same writers and designed to be the son of the Ranger’s nephew. He’d argued hard for the show to be made in hour-long format, but he was told to continue with the half-hour arrangement, which meant it struggled against Batman’s similar setup. Three incidents of crossover stories with Batman failed to assist ratings, and each episode was making a $40,000 loss when the plug was pulled after 26 of 30 planned outings.

Watch the Green Hornet and Kato Guest on ‘Batman’

Nevertheless, The Green Hornet did leave an indelible mark on entertainment in the form of Reid’s assistant, the chauffeur Kato, who was played by Bruce Lee in his first major role. Discovering Lee’s passion for martial arts, Dozier allowed him to take on the job of stunt master of the production, although it’s alleged his push-too-hard approach meant that other stuntmen didn’t like working with him. Through Kato he introduced kung fu to the masses, securing his own career and launching that of many others – even Williams learned a few moves to make the fight scenes more visually impressive.

“Kung fu is a Chinese form of combat; arts like karate and jiu jitsu derive from kung fu,” Lee told curious journalists in an early interview, describing his approach as “attack and defense simultaneously.” He explained that he hadn’t been able to expand his teaching program because “every day we’re shooting, you know; it’s pretty busy.”

Watch a Classic Kato Fight Scene from ‘The Green Hornet’

With the cancelation of The Green Hornet, Lee was free to pursue a world-class career; while Williams, who didn’t completely retire from acting, was free to become a security business operator and a reserve sheriff officer. “Maybe it’s a part of doing civic duty,” he reflected, sounding like the character he’d once played. “There’s a real need out there, I think, for an auxiliary or reserve core of people to get involved.” He noted that the show had made enough of an impact to mean he continued to receive fan mail. “I can always tell when I’m on the phone, and all of a sudden there’s a big dead pause,” he explained. “Then, ‘You sound like the Green Hornet!’”

Watch the First Episode of ‘The Green Hornet’