Through the 80 year history of the DC Universe, many things have changed - from the origins of its greatest heroes, to who those heroes actually are, down to the very history of the world itself.
Most of the time, DC platforms these 'retcons' (retroactive continuity, for you non-comic lingo types) through event stories that bring in dozens of heroes, villains, and plotlines under the guise that the DC Universe will "never be the same," a common refrain for comic stories that promise the world.
In some cases, such as the recent Dark Nights: Death Metal, those promises are seemingly delivered with sweeping changes that alter not just one world, but in the case of DC (and especially Death Metal) many worlds across a vast Omniverse of timelines and universes.
DC movies may be taking this same approach with its upcoming Superman reboot movie, which may take some cues from Superman stories that have spanned the Multiverse.
With that in mind, here are the DC comic book events that have had the biggest impact on the DC Universe.
10. Dark Nights: Death Metal
Speaking of which ...
While the returns are still very early, if DC's upcoming launch of the Infinite Frontier editorial era delivers on the promises of Dark Nights: Death Metal, it'll likely move up this list in the coming months and years.
As detailed here, the January 2020 finale of the Scott Snyder-written magnum opus event series is in Newsarama's view a pretty major reboot - one that could legitimately redefine the DC Universe.
Now whether this new architecture of DC canon and continuity pays real narrative dividends in the future remains to be seen, but the potential is there for what Snyder called an "Anti-Crisis" to find its way to near the top of the list where (if you keep reading) the original Crisis resides.
9. Green Lantern: Rebirth
This 2004-2005 limited series Green Lantern: Rebirth resurrected a dying Green Lantern franchise and started writer Geoff Johns' journey toward becoming DC's go-to event architect — and one of the company's most successful retcon artists, which he displayed in a big way here.
Green Lantern: Rebirth brought a disgraced Hal Jordan back from the dead, restore the charter's former heroic reputation, resurrect a huge, universe-spanning Green Lantern corps, and explain questionable areas of the Green Lantern mythos in fresh, new ways — all without dumping the continuity that had come before.
After its publication, the Green Lantern franchise became one of DC's strongest in publications, anchoring the Universe-wide Blackest Night just a few years later.
8. Zero Hour: Crisis in Time
You'll be seeing a lot of the word "crisis" in this list, but this 1994 event Zero Hour: Crisis in Time is specifically linked to the grand-daddy Crisis of them all — Crisis on Infinite Earths.
That earlier 1985 series completely rebooted the DCU and combined its multiple earths, but some confusion still remained almost 10 years later.
Characters like Hawkman and the Legion of Super-Heroes owe much of their post-Crisis continuity clean-up to the Zero Hour, which pitted a character named Extant (the former Hawk of Hawk & Dove – it's complicated) against the DCU and played with the idea of time itself.
7. DC Universe: Rebirth
This May 2016 one-shot by DC Universe: Rebirth Geoff Johns and several DC superstars brought back many of the relationships and characters that readers were missing since DC's 2011 reboot. It resurrected the long-missing Wally West, set up the return of the classic Superman, and also surprisingly set up the Watchmen universe crossover Doomsday Clock.
The newly re-numbered and re-branded series that followed restored some oomph to DC's publishing line by — as DC explained it — concentrating on each character's "core." The 'Rebirth' era restored numerous aspects of DC continuity that were previously lost, and opened the door to the current 'Infinite Frontier' concept.
6. Final Crisis
This 2008 series Final Crisis, written by Grant Morrison, focused on efforts by DC heroes to defeat the villain Darkseid as he plots to take over reality itself.
Hailed by some critics as a masterpiece for its mind-bending concepts, it was alternately called confusing by others for its fast-paced and content-crammed storyline.
By the time the series and its many tie-ins ended, Martian Manhunter was dead, Batman was believed dead (and had been forced back through time), and the continuity of three Legion of Super-Heroes teams was combined into one.
Besides its immediate ramifications, the story and its aftermath greatly influenced the recent Dark Nights: Metal series that rocked the DCU.
5. Death of Superman
Among all its accomplishments, perhaps the most penetrating aspect of 1992's 'Death of Superman' event was that it proved that even Superman could die.
Crossing into multiple series and tie-ins, the story showed how Doomsday defeated Superman, how the world reacted, and who showed up to take his place – the latter part featuring the introduction of several new characters who stuck around to help form the later DCU.
The event made mainstream news, sold like crazy, and not only influenced later comic book stories, but it was incorporated into DC's cinematic depiction of Superman as well, with part of the tale being adapted into Zack Snyder's Justice League.
4. Flash of Two Worlds
It's difficult to explain how important the 'Flash of Two Worlds' story was in 1961's The Flash #123. It not only introduced the idea of DC having an "Earth-Two," but it essentially debuted the idea of the Multiverse that is featured in DC comic books and TV shows today.
Written by Gardner Fox with pencils by Carmine Infantino, the story featured the new Flash, Barry Allen, being transported to the Earth where the original Flash, Jay Garrick, existed. The story explained how all the DC earths vibrate at specific frequencies, borrowing from theoretical science of the time.
The idea of traveling between worlds has shown up throughout DC's history and influenced comic books at other publishers since.
3. Infinite Crisis/52
It's tough to separate these two events because Infinite Crisis by Geoff Johns and Phil Jimenez led right into DC's ground-breaking, team-written-and-drawn weekly series 52.
The ramifications were numerous, but perhaps the biggest was the return of the DC Multiverse that had been eliminated in 1985's Crisis on Infinite Earths.
It all started in Infinite Crisis with the death of multiple characters and the hint that maybe the Multiverse could return. Then in 52, DC actually made the new Multiverse a reality, although limiting it to just 52 worlds.
And in the meantime, the publisher proved that a tighter shipping schedule could happen with modern technology — and still happens today with weekly limited-series a current publishing trend.
2. Flashpoint/The New 52
Whether readers loved or hated DC's 2011 reboot and total renumbering of its line — titled 'The New 52' — the fact remains that this event had major ramifications.
After the Flash traveled back in time in the mini-series Flashpoint and changed history, the continuity of the DCU changed. Some heroes became younger, others were eliminated altogether, and the event gave DC the opportunity to completely retool the origins of just about every single character and concept to which it owned the rights.
The timeline that had once stretched back to before World War II was now shortened to a five-year history and scores of characters were re-introduced as new, inexperienced superheroes — or weren't re-introduced at all.
The word "flashpoint" has been used for similar DC stories in other media - including an upcoming film - so this event's ramifications still live on.
1. Crisis on Infinite Earths
What can be said about the landmark 1985 series by Marv Wolfman and George Pérez that hasn't already been said?
Crisis on Infinite Earths changed the whole landscape of the DCU and served as the first time a comic book company would reboot its entire continuity to freshen its product — something that's much more frequent these days.
Crisis killed boatloads of characters (back when character deaths actually meant something), including the high-profile death of Supergirl and a sacrifice by the beloved Barry Allen version of The Flash, one that took him away from comic books for more than 20 years. Mostly, it cleaned up DC's continuity after 50 years of publication and allowed a new batch of writers and artists to re-invent them or give them new life.
Every DC event since owes its existence, really, to the original Crisis.
The story was adapted in 2019 and 2020 - surprisingly faithfully - for CW's Arrowverse.