If you know your comic book stuff, you are probably aware that the DC superhero Shazam was once called Captain Marvel. However many are only now discovering the fact with origin movies for both heroes hitting cinemas at the same time.

We know Captain Marvel best as Carol Denvers, MCU hero. Shazam, aka Billy Batson, is associated with DC.

It turns out though that Shazam's real name is Captain Marvel, but due to a legal battle that stretches back decades, he had to be renamed.

Captain Marvel debuted in the early 1940s at Fawcett Comics. Then DC sued Fawcett because he seemed too much like Superman. Fawcett was driven to stop making Captain Marvel comics after which DC bought the character, but forgot to trademark the hero’s name. Marvel Comics noticed the trademark omission and took advantage of the fact. Thus DC's Captain Marvel couldn’t legally use his own name and became Shazam!

It seems that the upcoming Shazam! movie wanted to avoid the can of worms entirely.

Director David Sanberg told UPROXX:

"Captain Marvel of Marvel is so established, and especially with another movie coming out almost the same month as us, it’s just like, let’s just go down the path of Shazam. Because that’s the more unique name as well."

Asked if they were at least allowed to mention the name, producer Peter Safran admitted:

"It was never really on the table. We never really talked about it."

'Captain Marvel's in cinemas now while 'Shazam!' hits theatres on April 5.