The Green Hornet is the title character of a middle 20th Century radio series, a middle 20th Century movie serial, a short-lived 1960s television series that starred Van Williams in the title role, and a 2011 full-length motion picture that starred Seth Rogen in the title role.
The Green Hornet is actually a heroic crusader against crime, but owing to an insidious propaganda campaign mounted against him that a major metropolitan newspaper, the Daily Sentinel, spearheads, law enforcement has been largely convinced that he is a criminal himself. The criminals he faces off against, when they are brought down, are misrepresented as the Green Hornet having eliminated competitors against himself.
The Daily Sentinel's publisher, Britt Reid, who had launched that campaign in the first place, is in reality secretly the Green Hornet, and is deliberately maintaining this campaign specifically to conceal the Green Hornet's motives and prevent anyone from suspecting the linkage between the two. Reid's manservant, Kato, secretly the Green Hornet's partner in his crusade against crime, is also one of the few people who know that "Britt Reid" is the Green Hornet's real name.
The character was created, as was the Lone Ranger, by George W. Trendle, who intended The Green Hornet to be to then-contemporary crime dramas what The Lone Ranger was to Western-adventure shows. The plots of stories in the two radio shows ran parallel, and indeed, Britt Reid was introduced to radio audiences as the son of Daniel John Reid Jr., whose uncle, John Daniel Reid, had hidden from his enemies using the alias of the Lone Ranger.