It's been 30 years since the world was gripped by Bat-Mania. "Batman" truly dominated the summer movie season in 1989, giving starving superhero fans a taste of a darker, more dramatic Caped Crusader. While we wait for the dark Knight to return to the big screen in 2021's "The Batman," learn more about the making of Tim Burton's epic superhero revamp.

1. The origins of "Batman" can be traced back to 1979, when producers Benjamin Melniker and Michael E. Uslan purchased the rights to the franchise from DC Comics in the hope of making a darker movie more in line with the original Bob Kane/Bill Finger comics.

2. The project went through numerous incarnations over the course of that next decade. At one point "Ghostbusters" director Ivan Reitman pitched a more comedic take starring Bill Murray as Batman and Eddie Murphy as Robin.

3. Despite this prolonged period of development, WB didn't officially greenlight "Batman" until Tim Burton's "Beetlejuice" became a box office success in 1988.

4. Burton has admitted to never having read the Batman comics before being hired as director, though this is due to his dyslexia rather than an actual distaste for the source material (as many detractors have claimed). Burton has also said the 1988 graphic novel "Batman: The Killing Joke" helped him gain a better handle on the Batman/Joker dynamic while preparing for the job.

5.Jack Nicholson negotiated an extremely favorable deal with WB that granted him top billing in the credits, control over his shooting schedule and percentage points of both the box office gross and merchandise sales.

6. In fact, Nicholson's deal is considered to be one of the most lucrative in Hollywood history. He's estimated to have earned at least $100 million from the franchise over the years, including being compensated for sequels in which he never appeared.

7. Nicholson may have eventually reprised his role had the series not been rebooted following 1997's "Batman and Robin." A planned fifth movie called "Batman Unchained" would have featured the Joker returning in the form of a hallucination caused by Scarecrow's fear gas. That story pitch also introduced Harley Quinn as the vengeful daughter of Jack Napier.

8.Robin Williams lobbied for the Joker role and came very close to winning the part when it appeared Nicholson would bow out. Williams' remained bitter about losing the role for many years, even refusing the opportunity to play The Riddler in 1995's "Batman Forever."

9.Michael Keaton improvised some of Batman's most memorable lines in the movie, including the now-iconic "I'm Batman." The script has the character instead saying, "I am the night."

10. The newspaper cartoonist's rendition of "The Bat-Man" is actually drawn by Batman co-creator Bob Kane. Kane was also supposed to have played the cartoonist, but he fell ill during filming.

11. To date, this is the only theatrical Batman movie to feature exactly one supervillain from the comics. Every other Batman movie has included at least two villains.

12.Pat Hingle (Commissioner Gordon) and Michael Gough (Alfred Pennyworth) are the only two "Batman" actors to reprise their roles in all three sequels.

13. Sam Hamm's original screenplay included a pre-Robin Dick Grayson. Child actor Ricky Addison Reed was cast in the role, but the character was cut when Warren Skarren revised Hamm's script shortly before filming commenced.

14. The ending was another source of many last-minute revisions. Originally, the climax revolved around an enraged Batman attacking Joker after the death of Vicki Vale.

15. "Batman" became the highest-grossing DC Comics movie of all time and wasn't unseated until 2008's "The Dark Knight."