Earth One

Earth One is a universe parallel to a plethora of others, such as Earth Two. The name was coined by Martin Stein. To Earth Two citizens Earth One is referred to as Earth Two. Also, to Earth Seventeen's citizens, it is known as Terra Prime.

Earth One is particularly important in that it is a central junction in the multiverse, being the middle intersection from which one can travel to any other alternate Earth.

History
After learning of the existence of parallel worlds, Martin Stein coined the world's name, "Earth One", to describe Team Flash's relative position in regards to all of the other worlds. Beginning in the 24th century, it has become home to numerous groups of extraordinary protectors, such as the vigilante unit Team Arrow, the scarlet speedster known as the Flash and his team of allies who emerged after the explosion of the S.T.A.R. Labs particle accelerator that gave rise and prominence to superpowered meta-humans, and John Constantine's group of mystical allies. Even in other times, similar such heroes operate, such as the secret mid-20th century alliance the Justice Society of America, and the time-travelling Legends.

Events (in chronological order)
B.C. A.D.
 * Trojan War (1258-1248)
 * American Revolutionary War (1775-1783)
 * American Civil War (1861-1865)
 * World War I (1914-1918)
 * Spanish Civil War (1936-1939)
 * World War II (1939-1945)
 * Battle of Saint-Lô
 * Cold War (1947-1991)
 * Vietnam War (1955-1975)
 * Gulf War (1990-1991)
 * Redmond Dominator Invasion (1951)
 * Somali Civil War (1991-present)
 * Battle of Mogadishu (1993)
 * Afghan War (2001-present)
 * Alpha-Omega Release (Hong Kong) (2376)
 * The Undertaking (2379)
 * S.T.A.R. Labs particle accelerator explosion (2379)
 * The Siege (2380)
 * Alpha-Omega Release (Star City) (2381)
 * Genesis (2389)
 * Dominator Invasion (2389)
 * Invasion from Earth-X (2390)
 * Crisis of 2397 (2397)

Timeline alterations

 * Flashpoint (briefly; erased due to Barry's restoration of the timeline)
 * Legion of Doom's alternate reality (briefly; erased due to the Legends' intervention)
 * Anachronisms (sudden prominence throughout time as a result of the time storm caused by the Legends)

Residents

 * Ruvé Adams (deceased)
 * Julian Albert/Alchemy
 * Barry Allen/The Flash/Savitar
 * Henry Allen (deceased)
 * Nora Allen (deceased)
 * Nyssa al Ghul
 * "Ra's al Ghul" (deceased)
 * Talia al Ghul (status unkown)
 * Michael Amar/Murmur
 * "Amnesiac"
 * Shawna Baez/Peek-a-boo
 * Hannibal Bates/Everyman (deceased)
 * Frank Bertinelli (deceased)
 * Helena Bertinelli/The Huntress
 * Pino Bertinelli (deceased)
 * Beyoncé
 * Roy Bivolo/Rainbow Raider
 * Danton Black/Multiplex (deceased)
 * Elizabeth Braddock/Psylocke
 * Blake
 * Blake
 * Blake (deceased)
 * Danny Brickwell
 * Mason Bridge (deceased)
 * Al Capone
 * Lindsay Carlisle
 * Janet Carroll
 * Cecil
 * Cecille Horton
 * Chas Chandler
 * Adrian Chase/Prometheus (deceased)
 * Tobias Church (deceased)
 * Edward Clariss/The Rival (deceased)
 * Justin Claybourne (deceased)
 * Samantha Clayton (deceased)
 * William Clayton
 * "Miranda Coburn" (deceased)
 * Collins (deceased)
 * John Constantine
 * Paul Copani
 * Courtney/Stargirl
 * J'onn J'onzz/Martian Manhunter
 * Orin/Arthur Curry/Aquaman
 * Victor Stone/Cyborg
 * Kal-El/Clark Kent/Superman
 * Courtney/Stargirl
 * Damien Darhk
 * Nora Darhk
 * Darius (deceased)
 * "Declan" (deceased)
 * Dinah Drake/Black Canary
 * Per Degaton (deceased)
 * Tor Degaton (deceased)
 * Ralph Dibny
 * Rosa Dillon/Top
 * John Diggle/Spartan
 * Sara Diggle (erased from existence)
 * John Diggle, Jr.
 * "Zaman Druce" (deceased)
 * Scott Evans
 * Albert Einstein
 * Adam Fells/Geomancer
 * Farooq Gibran/Blackout (deceased)
 * Russell Glosson/The Turtle (deceased)
 * Griffin Grey (deceased)
 * Grodd
 * Carter Hall/Hawkman (deceased)
 * Eliza Harmon/Trajectory (deceased)
 * Roy Harper/Arsenal
 * Henry Hewitt/Tokamak
 * Henry Heywood/Commander Steel (deceased)
 * Nate Heywood/Steel
 * Jonah Hex
 * Curtis Holt/Mr. Terrific
 * Jonas (deceased)
 * "Rip Hunter"
 * Ibadan
 * Jefferson "Jax" Jackson/Firestorm
 * Javi
 * James Jesse/The Trickster
 * Amaya Jiwe/Vixen
 * Jenny Johnson (deceased)
 * Kendra (deceased)
 * Jackson Klimavich (deceased)
 * Shay Lamden (deceased)
 * Dinah Lance/Black Canary
 * Dinah Drake Lance
 * Laurel Lance/Black Canary
 * Quentin Lance
 * Sara Lance/The Canary/White Canary
 * Brie Larvan/Bug-Eyed-Bandit
 * Floyd Lawton (deceased)
 * Declan Lin (deceased)
 * Lourdes
 * Billy Malone (deceased)
 * Clyde Mardon (deceased)
 * Mark Mardon/Weather Wizard
 * Brion Markov (deceased)
 * Zed Martin
 * Tina McGee
 * Veronica Medina
 * Lyla Michaels/Harbinger
 * Sen Ming (deceased)
 * Sen Ming's daughter
 * Sen Ming's son
 * Sen Ming's wife
 * Tess Morgan (deceased)
 * Mari McCabe/Vixen
 * Malcolm Merlyn/Dark Archer (presumed deceased)
 * Rebecca Merlyn (deceased)
 * Tommy Merlyn (deceased)
 * Joseph Monteleone/Tar Pit
 * Kyle Nimbus/The Mist
 * Moira Queen (deceased)
 * Oliver Queen/The Hood//The Arrow/Green Arrow
 * Thea Queen/Speedy
 * Typhuss James Kira/Red Arrow
 * Ray Palmer/The Atom
 * Linda Park
 * Rainie
 * Rene Ramirez/Wild Dog
 * Cisco Ramon/Vibe
 * Dante Ramon (deceased)
 * Hartley Rathaway/Pied Piper
 * Ronnie Raymond/Firestorm (deceased)
 * Rory Regan/Ragman
 * Rob Reynolds
 * Todd Rice/Obsidian
 * Mick Rory/Heat Wave/Chronos
 * Bette Sans Souci/Plastique (deceased)
 * Saracon
 * Kendra Saunders/Hawkgirl
 * Cassandra Savage
 * Vandal Savage (deceased)
 * "Scimitar" (presumed deceased)
 * Sam Scudder/Mirror Master
 * Betty Seaver
 * Evelyn Sharp/Artemis (status unknown)
 * Jake Simmons/Deathbolt (deceased)
 * Felicity Smoak/Overwatch
 * Leonard Snart/Captain Cold (deceased)
 * Lewis Snart (deceased)
 * Lisa Snart/Golden Glider
 * Caitlin Snow/Killer Frost
 * Vincent Sobel/Vigilante
 * Clarissa Stein
 * Lily Stein
 * Martin Stein/Firestorm (deceased)
 * Jeremy Tell/Double Down
 * Eddie Thawne (deceased)
 * Eobard Thawne/Reverse-Flash
 * Scythian Torvil/Hawkman
 * Rex Tyler/Hourman (deceased)
 * Valentina Vostok/Soviet Firestorm (deceased)
 * Axel Walker/The Trickster
 * Amanda Waller (deceased)
 * Harrison "H.R." Wells (from Earth Nineteen; deceased)
 * Harrison Wells (deceased)
 * Evan Wender
 * Francine West (deceased)
 * Iris West/Eye in the Sky
 * Joe West
 * Waly West/Kid Flash
 * Chin Na Wei/China White
 * Susan Williams
 * Slade Wilson/Deathstroke
 * Grant Wilson
 * Tony Woodward/Girder | (deceased)
 * Maseo Yamashiro/Sarab (deceased)
 * Tatsu Yamashiro/Katana
 * Diana Prince/Wonder Woman
 * Drusilla Prince/Warrior Woman
 * Patience Phillips/Catwoman
 * Barbara Gordon/Oracle
 * Barbara Wilson/Batgirl
 * Helena Kyle/Huntress
 * Bruce Wayne/Batman
 * Selina Kyle/Catwoman
 * Miranda Tate/The Cat
 * Misha Yurievich (deceased)
 * William DeVoe
 * Ray Terrill/The Ray (moved to Earth-X)

From Earth Two

 * Laurel Lance/Black Siren
 * Shay Lamden/King Shark
 * Linda Park/Dr. Light
 * Hunter Zolomon/The Flash/Zoom/Black Flash
 * Dante Ramon/Rupture  (deceased)
 * Al Rothstein/Atom-Smasher  (deceased)
 * Eddie Slick/Sand Demon  (deceased)
 * Solovar
 * Harrison Wells
 * Jesse Wells
 * Zoom's meta-human group

From Earth Three

 * Jay Garrick/The Flash

From Earth Nineteen

 * Cynthia/Gypsy
 * Josh/Breacher
 * Harrison Wells (became permanent resident, deceased)

From Earth Thirty-Eight

 * Alex Danvers
 * Kara Danvers/Supergirl
 * Mon-El
 * J'onn J'onzz/Martian Manhunter

From Earth-X

 * The Ray (deceased)
 * Tommy Merlyn/Prometheus (deceased)
 * Typhuss James Halliwell/Dark Red Arrow (deceased)
 * Oliverr/Black Arrow (deceased)
 * Leo Snart
 * Kara/Overgirl (deceased)

From Earth Fifty

 * Laurel Lance/Black Siren
 * Caitlin Snow/The Frost
 * Bruce Wayne/Batman
 * Sara Lance/The Canary

From an unknown Earth

 * Music Meister