Since his first appearance in 1939, Batman has become arguably the best known of all superheroes, having numerous comic series running alongside each other, multiple movies, a TV series, a lot of video games and a number of animated cartoons. 

Batman has a huge number of action figures, collectables, t-shirts, hoodies, Lego sets and merchandise available of him, his sidekick Robin and his army of villains - The Riddler, The Penguin, Two Face, Bane, Clayface, Ras Al Ghul, The Scarecrow, Poison Ivy, Catwoman and Harley Quinn to name just a few. 

However, one villain stands above all the others - The Joker. Based on Conrad Veidt's appearance in the movie, The Man Who Laughs, The Joker is easily the best known villain in comics. 

In the 1960's Batman came to television in the form of the campy series starring Adam West and Burt Ward. The series was a huge success and spawned a movie and so the comic adapted to mimic the series. However, by the 80's Batman was stale and the comics were in danger of cancellation.

In 1986 Frank Miller unleashed the mini series The Dark Knight Returns - a series set in the future where an old Batman faces The Joker one final time. Off the back of that success, Frank Miller was put in charge of writing the main series of comics in 1987. Miller took the comic in a darker direction immediately with the story Year One, a retelling of Batman's origin. 

Fans reacted positively and sales increased rapidly saving the book. In 1988 Batman had two huge events - The Joker murdered Robin while in a character defining one-shot, Batman and The Joker fought in the far more adult The Killing Joke. 

Batman was once again back at the top of the comics industry and has gone on to be a juggernaut for DC Comics, not to mention spawning the massive success that is Harley Quinn.