any number of comic book storylines involving Supergirl for its plot. Comic book readers know that the history of Supergirl is long, complex, and rife for adaptation.
Supergirl's journey through comic book history is one of the most dramatic and confusing of any character, though she has persisted through the decades to become one of the seminal characters of the greater DC Universe. Fans looking for more adventures with Supergirl will find plenty to keep them busy in the comics.
The Early Supergirls
Most fans today associate Kara Zor-El with Supergirl, but she isn't the only version of the character and wasn't even the first. Several takes on the concept of a female version of Superman predated her, including Lois Lane as Superwoman. She appeared in Action Comics #60 in May 1943 very early in the Golden Age of Comics. Lois doesn't actually become Superwoman but has a dream she is. Others would follow, including the first character to be called Supergirl in Superboy #5 from 1949. This character was a love interest of young Clark who didn't have powers.
Kara Zor-El
The true story of Supergirl begins with the debut of Kara Zor-El, the cousin of the Man Of Steel, in Action Comics #252 in May 1959. Co-created by writer Otto Binder and artist Al Plastino, she played much the same role as other sidekicks of the era, effectively an audience surrogate for young readers. Kara is introduced as the cousin of Kal-El, a survivor of Krypton sent to Earth to live with her heroic relative. They agreed to keep their connection a secret though, and Kara, in the guise of Linda Lee, actually grew up in an orphanage.
Argo City
Kara survived the destruction of Krypton along with many other people on a giant fragment of the planet that broke off. Argo City was one of the largest cities on the planet and survived the disintegration of Krypton thanks to an advanced protective shield. The planet then floated through space, an island lost at sea. The earliest version of Kara fled Argo City when the city finally succumbed years later, but later versions of her backstory would present Argo City in different ways depending on the needs of the story.
Comet The Super Horse
Supergirl arrived on the scene right at the beginning of the Silver Age of Comics, but her stories had many of the trappings of Golden Age stories, such as pet sidekicks. One of her most famous was Comet The Super Horse. Like other prominent super pets, Comet tagged along for many of her adventures.
Where things got truly strange was when a wizard turned Comet into a person and Kara fell in love with him. It was definitely one of the strangest romances in Superman-related comics and one of the stranger ones in comics history.
Modern Update
Kara's existence remained a secret for years until she revealed herself to the world in Action Comics #285 in 1962. This proved liberating for the character and she would go through a series of updates through the 70s and 80s. Her costume changed quite a lot, with her classic Silver Age look evolving into one that mirrored fashion trends from the era. Her 70s costume lost the skirt for what were essentially hot pants. Her 80s look incorporated a headband for a period of time. She also went through many careers, including becoming a reporter.
Death In Crisis On Infinite Earths
Supergirl continued as an important character in the Superman family of comic book titles for years until her shocking death in issue seven of Crisis On Infinite Earths. This 1985 mini-series completely reset DC Comics continuity by consolidating all parallel worlds and comic histories into one. Supergirl was one of the biggest casualties, with some at DC concerned that Superman wasn't unique enough because of all the Kryptonian survivors. As a result, she not only died but was completely erased from continuity. Though some parts of the Crisis comic would have been nice to see in the Arrowverse, Kara's death was probably not one of them.
Matrix
As is always the case in comics, death is never the end. Kara Zor-El was written out of continuity, but Supergirl was still a popular character. The hero returned a few years later in the late 80s, but with a radically different origin. This Supergirl debuted in 1988 wasn't Kryptonian or human, but a mass of protoplasm designed by Lex Luthor in an alternate reality. The Matrix, as it was known, eventually adopted the form of a young human woman who looked a lot like the original Supergirl.
Power Girl
Crisis On Infinite Earths was intended to clean the slate for DC Comics continuity-wise, but there were some dangling threads that proved hard to reconcile. One of them was Power Girl. Kara Zor-L hailed from the alternate reality of Earth-Two. She crossed over into Earth-One and survived Crisis, but her origin was completely revised in order to do so.
Her backstory was changed so that she was the descendant of an Atlantean sorcerer (as might be in the MCU). Later shifts in DC Comics continuity eventually placed her back where she started out on Earth-Two.
Cir-El
Many other versions of Supergirl have existed in the comics over the years (about as many versions as in the Supergirl television series). One of the most interesting is Cir-El, a version of the character who is a possible future daughter of Superman and Lois Lane. She first appears in Superman the 10 Cent Adventure #1 in 2003. Cir-El would alternate back and forth, sometimes uncontrollably, between a human persona known as Mia. She eventually returns to her native timeline.
The Return Of Kara
After several years of being out of the comics, the original Kara Zor-El returned to the role of Supergirl in 2004. Though DC Comics would continue to refine its complicated history with successive events like Final Crisis, New 52, and DC Rebirth, the overall trajectory of Kara in the last fifteen years has been more or less back to her roots. She is again the cousin of Kal-El, a survivor of Krypton, and has powers and weaknesses consistent with Superman's and her previous versions.
