Earth-One itself was populated by various individuals who resembled those of its primary Multiversal counterpart, Earth-Two. Some were direct parallels to their predecessors (ex. Superman (Earth-One) and Superman (Earth-Two)), some less so (ex. Atom (Al Pratt) and Atom (Ray Palmer)). The two Earths were closely linked in terms of parallel development, although Earth-Two individuals usually predated their Earth-One counterparts by a few decades.
The primary superheroes were limited to the western heroes of the eighteen hundreds and few others, until Superman arrived from Krypton and ushered in a new age of heroes. On this Earth, Superman had a career as Superboy and teamed with the Legion of Super-Heroes in the 30th century.
From the perspective of the Earth-One Universe, the first travel to another parallel universe occurred when The Flash (Barry Allen) accidentally changed his vibrational frequency to match that of Earth-Two, where he met Jay Garrick, the Golden Age Flash. That meeting resulted in years of interaction between the original super-hero team, The Justice Society of America, and their younger Earth-One counterparts, The Justice League of America.
As Barry Allen was the first traveler, the honor of naming the two Earths fell to him - his universe's Earth was called Earth-One, Jay Garrick's became Earth-Two. As noted years later by the elder Superman, they (the JSA) were too polite to mention that they were around first .
As Allen explained to Garrick in their first meeting:
- "..I vibrated so fast -- I tore a gap in the vibratory shields separating our worlds! As you know -- two objects can occupy the same space and time -- if they vibrate at different speeds!
My theory is, both Earths were created at the same time in two quite similar universes! They vibrate differently -- which keeps them apart! Life, customs -- even languages -- evolved on your earth almost exactly as they did on my Earth! Destiny must have decreed there'd be a Flash -- on each Earth!" 
10 billion years ago
Krona, a Maltusan, built a machine to discover the secrets of the very creation of the Universe. He watched through his portal a gigantic palm with a broth of stars in his hand as the machine exploded. Because of this act, the Multiverse and the Universe of Antimatter of Qward had been retroactively created. .
9 billion years ago
Driven by guilt over Krona's actions the Maltusans created Manhunters which they then replaced with the Green Lantern Corps. However, due to differences on how to deal with the evil created by Krona the Maltusans split into the Guardians of the Universe and Controllers. Shortly after this, the Monitor and Anti-Monitor were "born". They fought each other for a million years with a simultaneous attack knocking each other out for 9 billion years.
1 billion years ago
A great civilization, rich in magic and technology, leads to the formation of Atlantis. The earliest homo magi were the pre-deluge Atlanteans, and the greatest among them was Arion, the supreme sorcerer of Atlantis.
Modern civilization begins on Krypton.
Amazons, led by Hippolyta, migrate to Paradise Island after being briefly enslaved by Hercules; a group of them, led by Atalanta, migrate to Amazon rainforest.
The Homo Magi find a hidden land in Turkey in an attempt to keep their lineages pure. 
Possible Future Events
It should be noted there was no "set" future for Earth-One but rather a series of possible futures.. As a result trips into "the future" were in reality a trip into a future for Earth-One.
Eobard Thawne discovers the Flash's costume in a time capsule and devises a way make a costume that give him super speed with which he goes on a crime spree. The Flash arrived in the 25th century to stop the atomic clock buried in the capsule from going off like an atomic bomb and defeated Thawne.
Earth-One had at least two possible 30th centuries: the Legion of Superheroes and Kamandi. The Time Trapper channeled the power of the Green Lantern Corp to eliminate all futures except the Kamandi one and Superman was manipulated into fixing the problem by a green lantern.
In the far future, criminals who had been found guilty of particularly heinous crimes were sentenced to be sent to the Earth of the 51st century, which was, during that period of history, a desolated planet. On one such occasion, a thief known as Mazdan was sent into this dystopian future via a golden time-capsule. However, after an accident occurred, he was sent into the past instead, where, during the mid-twentieth century, the Flash foiled his robberies and sent him back to his future time period in order to be sentenced for his crimes.
In the year 121,970 the Earth is a desolate world poisoned by an atomic war.
In one future, in the year 824,057 the sun turned red and become hotter causing drought to the point that atomic power had to be used to manufacture water but eventually this proved ineffective and everyone left the planet. Superman was tricked into the 10,001th century of this future by the Superman Revenge Squad but was able to aid from robot duplicates of Superman's friends and enemies and made his way to his Fortress of Solitude. Using the materials there he returned to his own time.
In another future, Earth is rendered a globe of toxins thanks to a million years of pollution, war, and abuse. Superman, unable to stand some garbage robots destroy his adopted home planet due to it being an eyesore, drives off the garbage robots and uses his superpowers to restore the Earth to a livable state.
During the Crisis on Infinite Earths, Earth-One was destroyed. The New Earth that emerged after the Big Bang possessed elements of Earth-One's history, along with elements similar to that of Earth-Two, Earth-Four, Earth-S, and Earth-X. However, the events of Convergence restored it to the Multiverse.
Several of Earth-One's most famous cities have no direct counterparts on "nearby" parallel worlds such as Earth-Two or Earth-S. Examples include:
A significant number of modern nations, populated by regular human beings, existed uniquely on Earth-One, and many of these had no direct counterparts on "nearby" parallel worlds such as Earth-Two or Earth-S. Examples include:
- Peccador, a South American former dictatorship, became a republic in 1959.
- Rutovia, a European monarchy, until at least the 1960s.
- Xenovia, an island monarchy, until at least the 1960s.
A significant number of alien outposts, secret kingdoms, and lost civilizations existed uniquely on Earth-One, and many of these had no direct counterparts on "nearby" parallel worlds such as Earth-Two or Earth-S. Examples include:
- Abyssia, an underground monarchy, accessed from a secret location in Switzerland. The ruling elite of this kingdom had telekinetic super powers.
- Aqua, an undersea kingdom.
- Atlantis and Tritonis
- Dinosaur Island
- Lost City, on a small island in a dense fog, a city that has been separated from the world for centuries, ruled by a queen.
- Lost Land, in the mountains, an abandoned outpost of an alien civilization.
- An unnamed, untouched medieval town, in the Swiss Alps, where no snow falls. The people of this town seem to be immortal, and their leader, Rafsu, has telekinetic super powers.
- Paradise Island
- Sunken Island, a 700-year-old Chinese settlement, inside a submerged island.
- An uncharted tropical island in the Atlantic Ocean, site of a 900-year-old Norman/Saxon settlement.
- An undiscovered civilization, beneath the Earth's surface, which created a robot in the image of Superboy.
The properties of matter, laws of physics, and principles of chemistry were very different on Earth-One from those of our own world, or of “nearby” parallel continuums either. For example, there is no record of a “Speed Force” at work in Earth-One.
- 1959, Loren's De-Evolution Ray,
- 19(??), Hall's Nth-metal Antigravity Equipment,
- Elements such as Amnesium exist on Earth-One and New Earth, while seemingly not existing on Earth-Two.
- Amazonium, Kryptonite, and Nth Metal exist on Earth-One, and in several "nearby" parallel universes, such as Earth-Two and Prime Earth, while seemingly not existing on others, such as Earth-S and the Quality Universe.
Many devices, gadgets, vehicles, and weapons were built on Earth-One that could never have been built or made to work on our own world.
- 1958, Amazonian Invisible Airplanes,
Robotics, Sensors, Computers, Communications, Cybernetics
- 1948, Amazonian Mental Radio,
- The Earth-One Universe is not known to have existed to the general populace of New Earth. Part of the Pre-Crisis Multiverse.
- Inconstancies regarding certain "Earth-One" stories with Earth-One continuity resulted in many stories being retroactively assigned to a parallel Earth with Earth-Thirty-Two being the largest of these. More over continuity issues between Earth-Two and the actual Golden Age character suggested the existence of an Earth-Two-A. As a result it is unclear if Earth-One's first appearance really was More Fun Comics #101 or that was actually a Earth-Two-A story.
- Detective Comics #327 has been designated by DC as the first appearance of both the Earth-One Batman and Gotham.
- The Crisis on Infinite Earths: The Compendium lists an "Earth-B2" which refers the reader back to an nonexistent Earth-Forty-Six listing. What this reality was and how it differed from "Earth-B" (Earth-Twelve and Earth-Thirty-Two) is unknown.
- Because the differences between Earth-One and Earth-Thirty-Two characters is relatively minor the DC Comics Database has decided to use the Earth-One versions for the details that are identical.
- Earth-Two superheroes appeared on Earth-One beginning with The Flash #123. The concept of Earth-Two and Earth-One was developed by writer Gardner Fox after an initial concept by Julius Schwartz.
- However, Schwartz's initial idea was that the original Golden Age characters existed in "Earth 1" and the current Silver Age characters in "Earth 2". This concept was mixed up, resulting in the current universe designation.
- Despite the nearly identical names "Earth One" is a totally different reality.
- No trivia.
- Characters from Earth-One
- Other things related to Earth-One
- Earth-One's Comic Appearances
- Reality Gallery: Earth-One
Links and References
- ↑ Superman's Pal, Jimmy Olsen #117
- ↑ It should be that there are some contradictions between issues as to when (or even if) events happened. Some of these events were assigned to other Earths while others were not.
- ↑ Infinite Crisis #2
- ↑ The Flash #123
- ↑ Crisis on Infinite Earths #7
- ↑ Crisis on Infinite Earths #7 pg 10
- ↑ Crisis on Infinite Earths #7 pg 11
- ↑ In Green Lantern (Volume 2) #90 it is stated that a precursor to the Green Lantern Corps existed only 40,000 years ago but this is refuted in other stories which puts the formation of the Green Lantern Corps in its current form as at least 3 billion years old.
- ↑ Justice League of America #10
- ↑ Arion Lord of Atlantis #1 (letter's page)
- ↑ Justice League of America #165 pg 11
- ↑ Blackhawk #258
- ↑ World's Finest #93
- ↑ Superman #295
- ↑ The Flash #139
- ↑ Superman #295
- ↑ Showcase #4
- ↑ Action Comics #386
- ↑ Action Comics #300
- ↑ Action Comics #387
- ↑ Blackhawk #143
- ↑ Wonder Woman #98
- ↑ Wonder Woman #98
- ↑ Man of Two Worlds: My Life in Science Fiction and Comics (Julius Schwartz's autobiography)