Superman and Batman debuted only a year apart and they both rocketed to popularity. To make a splash at the 1940 New York World’s Fair, DC Comics put these two heroes together for the first time on a special edition fair comic book. On the pages inside, however, they both had completely independent stories.

In the spring of 1941 this trend continued with the introduction of World’s Best Comics (known as World’s Finest Comics from issue #2 onward). Every issue would feature Superman, Batman, and Robin, yet their stories had no crossover whatsoever on the inside. They appeared inside a comic for the first time in All-Star Comics #7 (October-November 1941), but it was simply to stand next to each other while donating money to war orphans and accept honorary membership into The Justice Society of America.

Once again, the Superman radio show would beat the comics to the punch. The first time they worked together in an actual plot was during a radio series titled “The Mystery of the Waxmen” in March 1945. 

Superman went out looking for the constantly-in-peril Lois and Jimmy and found them clinging to a busted-up boat in the bay along with a boy who he recognizes as Robin. Once he rescues them, Superman eventually chats with Robin one-on-one, learning that his secret identity is Dick Grayson and that Batman has disappeared. Before Robin was attacked, he heard the bad guys talking about getting paid by a man named Zoltan. They go together to Zoltan’s Wax Museum to see what clues they can find. They wander through and discover a wax figure of Batman!

Unfortunately, that’s the last of their first meetup that still survives today, as many of the Superman radio episodes are lost. On the bright side, DC adapted this story into a comic decades later in World’s Finest Comics #271 (September 1981) via a Superman flashback. They discover that the figure is actually the real Batman encased in wax. Superman busts him out and Batman explains that all of the wax figures are famous scientists that Zoltan is smuggling to deliver to the Axis Powers. Superman, Batman, and Robin go after Zoltan and his men, win handily, and gather for a firm handshake.

Superman: Well, that’s that! Hope we three can work together again one of these days.

Robin: We’ll hold you to that, Superman!

Batman: Right! After all, if not for you two, I’d be as good as dead.”

World’s Finest Comics #271

Throughout the rest of the Superman radio show, which concluded in 1951, Batman and Robin would appear on a total of more than 200 episodes. 

It wasn’t until a year after the radio show was over that Superman and Batman finally teamed up in the comics. Superman #76 (May-June 1952) begins with the following intro.

“Superman, mighty Man of Steel whose super-powers have conquered catastrophes and wrecked wrong-doers! Batman, hooded foe of crime whose flashing feats have crushed crooks for years! Are any two names in the world more famous than these? Yet these two mighty champions of the right have never met — until now! Yes, at long last Superman and Batman meet face to face on a voyage of peril — and strange and startling is the outcome when two legendary figures form ‘The Mightiest Team in the World!’”

Superman #76

After Batman nabs the last criminal on Gotham’s wanted list, Bruce Wayne decides to “relax and forget crime, for a change,” booking a trip on the cruise ship Varania. Little did he know that Superman was also taking a break on that same ship. In fact, the cruise was overbooked and Clark Kent and Bruce Wayne were forced to share a room. Almost immediately they discover each other’s secret identities.

Of course, Lois Lane lands a ticket as well and they must preserve their secret identities around her while trying to solve a case of missing diamonds. They spend the whole time battling over Lois’ affections, even performing feats of acrobatics and strength for the passengers. By the end, they decide that they’ll both ask her to dinner to see who she prefers. In a shocking twist, Robin swoops in to steal her away on a date.

Eventually, World’s Finest Comics would finally start teaming Superman and Batman in storylines as well. By the 1950s, superheroes were dwindling in popularity and DC had to cut pages from the series. Instead of having separate stories for both heroes, they had to combine them into one. World’s Finest Comics #71 (July-August 1954) kicked off the new format with a costume-switching scheme. All you need to know is that at one point Bruce Wayne punches out some lions.