Before Crisis on Infinite Earths was published, DC storylines had many continuity problems; no character's backstory was entirely consistent and reliable. DC's oldest superhero, Superman (sole survivor of the destroyed planet Krypton), could not originally fly; his strength came from evolving on a planet with stronger gravity than Earth's. He was later depicted flying, with his powers explained as deriving from Earth's yellow sun. Superman's history later incorporated his exploits as Superboy. More Krypton survivors (including Supergirl, a dog named Krypto and the inhabitants of the bottle city of Kandor) were introduced, contradicting the original premise that Superman was the sole survivor of Krypton's destruction.
Issues also arose about the age of some characters. Batman (an Earth-born human without superpowers) retained his youth and vitality well into the 1980s despite his World War II heroism, and his sidekick Robin took over 30 years in real time to graduate from high school. Characters such as the Flash, the Atom and Green Lantern appeared in conflicting storylines, with differing origins and powers.
The biggest perceived problem was DC's vast array of parallel Earths. Beginning as a one-off story in Flash (vol. 1) #123, the Silver Age version of the Flash met his Golden Age counterpart and the two shared an adventure. This pairing proved so popular that various other Golden Age superheroes at DC were revived, with the explanation that they lived on a parallel Earth, dubbed Earth-2, while the younger Silver Age superheroes lived on Earth-1. Over the years, various writers took liberties creating additional parallel Earths as plot devices, until in the early 1980s, it was perceived by DC management as not being reader-friendly enough for new readers to be able to keep track of.
Marv Wolfman and Len Wein saw Crisis as a chance to clean up DC's convoluted continuity. The term "Crisis" denoted an inter-dimensional crossover, similar to the annual Justice League–Justice Society crossovers that began with "Crisis on Earth-One".
Early in planning, a list was made of characters that were part of the DC Universe. The crossover was fleshed out and coordinated at a meeting attended by president Jenette Kahn, Paul Levitz, vice president and executive editor Dick Giordano and DC's editors. The groundwork for Crisis was laid the year before it was published and made use of a character (the shadowy, potentially villainous Monitor) who had been introduced in The New Teen Titans vol 1 #21 (July 1982) A January 3, 1983 memo instructed writers to use the Monitor character twice in the coming year but not to show him with his assistant Lyla the only on-panel character (who would first appear in The New Teen Titans Annual vol 1 #2
When Giordano (the series' initial inker) had difficulty meeting deadlines while continuing as DC vice-president and executive editor, editorial coordinator Pat Bastienne reassigned the inking to Jerry Ordway despite Giordano's objections. According to writer Steve Gerber, Crisis on Infinite Earths "got virtually no promotion ... How many handouts did you see? How many posters did you see in people's windows? How much information was really distributed to the press and how much was gotten just by individual reporters going to Marv Wolfman and [Crisis artist] George Pérez?" Despite this the series was successful, renewing interest in the company's books and attracting readers with the slogan, "The DC Universe will never be the same".
The conflicting origins and stories of the DC universe are explained as a Multiverse, containing many parallel universes and alternate versions of the characters, with the primary DC continuity referred to as Earth-1. A cosmic being known as the Monitor supervises many of these realities, but is opposed by his counterpart the Anti-Monitor, who comes from an antimatter universe and begins destroying many of the realities with a wave of antimatter, to replace them with his own.
The Monitor is murdered by his protege, Harbinger, who is possessed by one of the Anti-Monitor's demons; his death releases enough energy to project the last five parallel Earths into a protective limbo. The Anti-Monitor recruits Psycho-Pirate to his cause, infusing him with part of his power to manipulate the heroes of Earth-4, Earth-S and Earth-X against the rest; this fails when all five Earths enter the limbo universe. Harbinger recruits heroes from the remaining Earths to lead an assault on the Anti-Monitor in the antimatter universe, using Alexander Luthor, Jr.'s powers to open a portal between the limbo and antimatter universes. Pariah tracks down the Anti-Monitor at his fortress, and the heroes destroy a converter powered by stellar energy to destroy the last five Earths; the injured Anti-Monitor retreats and Supergirl dies.
During a lull in the war the villains unite under Brainiac, who kills Earth-Two's Alexei Luthor while recruiting the Earth-One Lex Luthor to conquer the remaining Earths. The Anti-Monitor tries to use an antimatter cannon to penetrate the limbo universe and destroy the five partially merged Earths. The Flash (Barry Allen) dies stopping this attempt. A furious Anti-Monitor vows to travel back through time to prevent the creation of the multiverse. The Spectre unites the heroes and villains by warning them about the Anti-Monitor's plan; the heroes travel back in time to stop the Anti-Monitor, while the villains travel back in time to the ancient planet Oa to prevent renegade scientist Krona from creating the technology necessary for the Anti-Monitor's plan to succeed. The villains fail, and Krona continues his experiment. The Anti-Monitor waits for Alex Luthor to reopen the portal between the positive and antimatter universes, capturing the heroes, but a magically empowered Spectre creates an energy overload which shatters space and time. The five Earths merge into a single shared universe, and the superheroes return to the present; only those present at the dawn of time remember the original realities.
A cosmically empowered Anti-Monitor attacks again, transporting the new Earth to the antimatter universe and summoning a horde of shadow demons. He falls in a carefully planned counterattack culminating in a battle with Kal-L (the Earth-Two Superman), Alexander Luthor of Earth-Three and Superboy of Earth-Prime, with help from New Gods adversary Darkseid. In this final battle the Anti-Monitor, reduced to a flaming head, crashes into a star and dies. As they are the only four who remember the original past, Alex sends Earth-Two Superman, Earth-Two Lois Lane, Earth-Prime Superboy and himself to a pocket "paradise" dimension.
According to George Pérez in a Wizard magazine interview in 1994, Chris Claremont suggested that Superman of Earth-One dies in the final battle with the Anti-Monitor in issue #12. After the Anti-Monitor was destroyed for good, Kal-L from Earth-Two realizes that he is now alone, without his Earth, without his Lois, and now the new single Earth is without a Superman. Then he remarks, "Don't need this anymore," and brushes the white dye off his hair and other make-up that he apparently used to make himself look aged. The other heroes are surprised by this and Kal-L simply explains that he had stopped aging when he reached the peak of his powers. He returns with the other heroes to the new post-Crisis Earth, taking the place of the Earth-One Superman.
If this idea had been used, then The Man of Steel would have marked the return of the "Original Super-Hero", as Kal-L (now switched to Kal-El) begins his life on the post-Crisis Earth, which is similar to his old life, but with distinct differences. Despite this "culture shock," Kal-L endures and is given a new lease on life by being deposited back to the early days of the modern heroic age of the post-Crisis Earth. However, this was discarded when the John Byrne version of The Man of Steel was planned.
* Not bannered as Crisis crossoversAll-Star Squadron #58-60
Green Lantern (vol. 2) #199-200
Infinity, Inc. #27, #30
Justice League of America #246
Last Days of The Justice Society Special #1
The Legend of Wonder Woman #1-4
Crisis on Infinite Earths created a new universe with a new backstory, and revised DC Universe characters refer to a past Crisis. In this history many heroes opposed the Anti-Monitor, who tried to destroy the positive-matter universe. The heroes do not know that they fought to save a multiverse because their memories of the Crisis #10 battle at the dawn of time have been erased.
The following DC characters were shown to have died during Crisis on Infinite Earths:
A cybernetically enhanced Gunner of The Losers appears in 2000's Creature Commandos. In a 2010 story set on July 4, 1976, the Losers survive World War II. In a Hawkman issue, Nighthawk is believed to have died under different circumstances and is a reincarnation of the Golden Age Hawkman after Prince Khufu.
The Superman reboot erased Lori Lemaris' death; she is reintroduced as able-bodied, with a "leg-changing" ability. The Crime Syndicate reappears three times: as Qwardians (fought years ago by the Justice League), after Zero Hour as people from the Earth of the antimatter universe and as the Crime Society of America in 52 and Countdown. In James Robinson's Starman comics Prince Gavyn's spirit survives, bonding with Will Payton to create a new Starman.
Psimon is resurrected. Mark Merlin, the human host of Prince Ra-Man, does not die with him but is "freed" from his possession. Twenty-three years after his death in Crisis, Barry Allen returns to the DC Universe on the last page of Grant Morrison's Final Crisis #2.
Several new characters were introduced in Crisis; the Monitor's assistant, Harbinger, and scientist Pariah played major roles in the story. Lady Quark was introduced as a survivor of one of the destroyed worlds. A new Doctor Light, a female hero, was introduced. Former Charlton Comics characters (notably Blue Beetle II) were introduced to the DC Universe.
After the Crisis, former Kid Flash Wally West assumed the mantle of the Flash. Jonah Hex was transported to a post-apocalyptic future, but this was unpopular and later stories brought him back to the Wild West. Justice Society of America member Wildcat was replaced by his goddaughter, Yolanda Montez, and became a member of Infinity, Inc. with Rick Tyler Hourman II and Beth Chapel (Doctor Mid-Nite). The Guardians of the Universe left for an unknown dimension and the Green Lantern Corps was reorganized, with Hal Jordan leading an Earth-based team. The surviving Justice Society members left for Limbo with Wildcat Ted Grant.
The story introduces the good Monitor and the evil Anti-Monitor, created by the experiment which created the multiverse. The Monitor made cameo appearances in DC comic series for two years before Crisis. At first he appears to be a new supervillain, but with the onset of the Crisis he is revealed as working on a plan to save the multiverse from destruction by the Anti-Monitor.
At the 2008 New York Comic Con, Dan DiDio said that Crisis on Infinite Earths was the first of a trilogy of "Crisis" limited series describing stages in the development of the DC multiverse; Crisis on Infinite Earths represented the "death of the multiverse", Infinite Crisis the "rebuilding of the multiverse" and Final Crisis the "final saga of the multiverse". In an October 2, 2011 post on his Facebook page, DiDio implied that Crisis On Infinite Earths, Infinite Crisis and Final Crisis did not occur in the DC New 52 universe. According to John Lichman's "DC New 52 Timeline So Far", this clarified an earlier assertion by DiDio: "Brace yourself, but after further review, there have been no Crisis events in the New DCU".
The Convergence (2015) crossover officially retconned the events of Crisis after heroes in that series went back in time to prevent the collapse of the Multiverse. However, the actual events that occurred when the Crisis' erasure of the multiverse was averted have yet to be disclosed. Whether this means that the pre-Crisis Supergirl and Flash did not die during the recalibration has yet to be clarified. Also left unanswered is the relationship between the Pre-Crisis, Hypertime, 52, and post-Flashpoint multiverses.
An unpublished Crisis on Infinite Earths story, written by Marv Wolfman with art by Paul Ryan and Bob McLeod, was published in the February 1999 Legends of the DC Universe: Crisis on Infinite Earths #1. Its events occur during and after Crisis on Infinite Earths #4, and it has the only appearance of Earth-D. The Flash of Earth-D is Tanaka Rei, a Japanese man who idolizes Barry Allen. Allen and Rei meet in Crisis on Infinite Earths when Barry returns from the 30th century to the wrong universe. Since that Earth is under attack by shadow demons, Barry calls on the Justice League and Rei calls on the Justice Alliance (his world's version of the Justice League).
Another untold Crisis-related story by Wolfman was published in August 2011 as part of the DC Retroactive series. Illustrated by Sergio Cariello and Curt Swan and set in 1984, Superman - The '80s #1 describes Destiny showing the pre-Crisis Superman images of future disasters (such as No Man's Land, Identity Crisis, his own death and the death of Supergirl) in the forthcoming Crisis. Superman vows to fight on despite the grim future, and Destiny reveals herself as Harbinger.
Blackthorne Comics published a two-issue miniseries, Freak-Out on Infant Earths, in 1987. In Marvel Comics' Mighty Mouse #4-5 (1991), entitled "Mices on Infinite Earths", Mighty Mouse meets Mighty Mousette and helping the Minotaur, Harebinger and Piranha fight the evil and powerful Anti-Minotaur. George Pérez drew the cover of issue #4 (parodying Crisis on Infinite Earths #7) and issue #5, parodying Crisis on Infinite Earths #12. The Crisis, other crossovers and "event" comics were parodied by Simpsons Comics in the Radioactive Man series.
The series finale of Green Lantern: The Animated Series featured a storyline that involved a character going back in time to re-shape the creation of the universe. In this version, the villain was the sentient robot Aya, who had gained control of the Anti-Monitor's body and sought to erase emotion from the universe.
In 2016, DC Comics, in partnership with Kentucky Fried Chicken, created a single issue mini comic called the "Crisis of Infinite Colonel's". This one off story featured Colonel Sanders in many of his multiverse iterations teaming up with a female Flash to restore memories of the Colonel's Secret Recipe. Memories of the recipe had been stolen by the villainous Earth 3 counterpart Colonel Sanders and an amalgamation of Colonel Sanders and Gorilla Grodd named Colonel Grodd.
For the 20th anniversary of Crisis on Infinite Earths, DC Direct released three series of Crisis action figures. The first series included Earth-Two Robin, Supergirl, the Monitor, Harbinger and Psycho-Pirate. The second series included the Flash (Barry Allen), Earth-Two Superman, the Anti-Monitor, Lex Luthor and Brainiac, and the third series included Earth-Prime Superboy, Batman, a Weaponer of Qward, Earth-Two Huntress and the female Dr. Light.
iBooks (distributed by Publishers Group West) novelized the comic-book miniseries with Marv Wolfman, one of its writers, narrated by Barry Allen. The hardcover edition (ISBN 1-5968-7290-X) was published in April 2005 and the paperback edition (ISBN 1-5968-7343-4) was published the following February. Its cover art was by George Pérez and Alex Ross. GraphicAudio, which had produced audiobooks of Infinite Crisis and 52, released an audiobook version of Crisis on Infinite Earths based on the novel in May 2009.Crisis on Infinite Earths #1-12 (April 1985 – March 1986) was published in hardcover (December 1998; ISBN 1-56389-434-3) and trade paperback (January 2001; ISBN 1-56389-750-4) editions, with cover art by George Pérez and Alex Ross.
Official Crisis on Infinite Earths Index (March 1986) describes each issue in the series, lists alternative Earths and provides a history of the multiverse concept.
Official Crisis on Infinite Earths Cross-Over Index (July 1986) summarizes every comic-book issue connected to the Crisis storyline, describes alternative Earths and lists every character in the Crisis series.
Crisis on Infinite Earths: The Absolute Edition (November 2005; ISBN 1-4012-0712-X) is an oversized, slipcased, hardcover edition. The first volume reprints the limited series, and the second volume includes scripts, commentaries, retrospectives and the two indexes.
Crisis on Infinite Earths Deluxe Edition (hardcover, October 2015, ISBN 1401258417). Includes the entire Crisis maxi series and the 2-issue series History of the DC Universe and other bonus material.
In the first season of The Flash, Harrison Wells has a newspaper from the future which reads "Flash Missing, Vanishes in Crisis" which is a reference to the comic. In the second-season finale, "The Race of His Life," Barry Allen creates a time remnant to stop Zoom's magnatar, which could destroy the multiverse by channelling the energy generated when Barry races his new enemy, Zoom. The time remnant runs at high speeds to stop it and save the multiverse by generating a counter-pulse to the magnetron's frequency, but disintegrates in the process, similar to Barry's death in Crisis on Infinite Earths.
In the Supergirl episode "Worlds Finest", Kara tells James "I just wanted to talk to you about infinite earths". In season 2 episode "The Last Children of Krypton", Superman carrying Supergirl's body is a reference to the comic book cover.