This took me a while, but here's my timeline, keep in mind GvsKG and GMK do not occur in this timeline:
251.4 MYA: King Ghidorah happens upon a planet rich with life (Earth). The Earth in defense creates Bagan, Balkzardan, Battra, and the Mothra. They fail dramatically.
145.1 MYA: King Ghidorah arrives on Earth once again to feed off of its inhabitants; is met with resistance from a peculiar advanced Mothra (Leo); looses both tails before being driven off back into space, and towards Mars…
65 MYA: One of the tails generates into Desghidorah. Desghidorah manages to wipe out the majority of all prehistoric life before finally being sealed by the Mothra.
??: The kingdoms of Mu, Nilai Kanai, and Seatopia are swallowed up by the Earth. Mu and Seatopia continued to thrive, whereas Nilai Kanai ceased to be.
680: The other tail manifests into Orochi. With the Earth created guardians sealed by time itself, a spiritual entity manifests itself into the being known as Utsuno Ikusagami. Orochi is defeated and sealed in Mt. Fuji.
1950’s: Several nuclear tests are conducted off the shores of Japan by the USA.
1954: The first Godzilla appears and is killed by the Oxygen Destroyer.
1955: A second Godzilla appears along with the first Anguirus. This Anguirus is killed by Godzilla II, who in turn is sealed in ice on an island north of Japan.
1956: A species of prehistoric dragonfly nymphs, Meganulon, appear. Two gigantic pterosaurs, Rodans, awaken as well. Both die in a volcanic eruption, and rumors of a recently hatched egg go unnoticed.
1957: Mankind makes first contact with an extraterrestrial race known as the Mysterians. The Mysterians prove to be hostile and unleash their war machines, the Mogera, upon Japan. They are defeated and driven off.
1958: A prehistoric reptile, Varan, appears and is seemingly destroyed. No body was ever recovered.
1961: The kidnapping of two miniature priestesses from Infant Island awakens a Mothra. The priestesses are returned and Mothra returns to her island home.
1962: An American nuclear submarine accidentally unleashes Godzilla II from his icy prison. King Kong and Oodako are discovered on Farou Island. Kong is captured and brought to Japan, where he does battle with Godzilla II before leaving, Godzilla II seemingly killed.
-A mammoth walrus, Maguma, is discovered in Antarctica.
1963: Mu declares war on the surface world. The flying battleship known as the Gotengo is tasked with bringing their empire down. The first Manda appears, and was seemingly destroyed in the destruction of Mu.
1964: Godzilla II appears once again, forcing Japan to call upon the aid of a reluctant Mothra, who has had her egg stolen by a corporation known as Happy Enterprises. Mothra is killed, but the egg hatches two larvae that go on to defeat Godzilla II, though one of the larvae is killed as a result of the fight.
-King Ghidorah returns, and a third Rodan appears. The surviving Mothra Larva manages to convince a warring Rodan III and Godzilla II to drive off Ghidorah.
-A giant jellyfish-like space monster, Dogora, attacks Japan in search of food.
1965: Mankind once again makes contact with alien life on Planet X, who are seemingly plagued by none other than King Ghidorah. Humanity loans them Rodan III and Godzilla II so that they may be able to drive off the King of Terror once more. It all turns out to be a ruse, however, as the Xiliens have placed Godzilla II and Rodan III under their control, along with Ghidorah, and have their eyes set on Earth . They are seemingly defeated, and a freed Godzilla II and Rodan III drive off Ghidorah once again.
-A boy that had consumed the heart of Frankenstein’s Monster after the bombing of Hiroshima is discovered. The boy grows to gargantuan proportions and does battle against an awakened man-eating dinosaur, Baragon, before being dragged to his watery death by Oodako.
1966: The terrorist organization known as the Red Bamboo is accidentally discovered by a group of shipwrecked commoners on Letchi Island. Under their “control” are the monsters Ebirah, and Ookondoru. Godzilla II is discovered to be sleeping on this island and is awakened. Ookondoru is fried to a crisp, and Ebirah is driven off, but not before making short work of his so-called masters.
-Oodako is surprise-attacked by a Frankenstein-like monster, Gaira, during his attack on a cargo ship. Gaira terrorizes the coastline of Japan before being lured inland, and is nearly killed, if not for the intervention of his brother, Sanda. Unfortunately, the brotherly love does not last long, and the Frankenstein monsters fight each other all the way out into Open Ocean where they are killed by an erupting underwater volcano.
1967: On Solgell Island, a giant species of praying mantis, Kamacuras, is discovered. Weather controlling tests further enlarge these mantids, uncover a giant egg, as well as awaken the giant theropod, Gorosaurus. Godzilla II arrives on the island just as the egg is about to hatch into Minilla. A giant spider, Kumonga, is later also discovered. Solgell is later classified as Monster Island.
1968: A second Anguirus emerges and takes residence on Monster Island, as well as Baragon, Varan, Ebirah, and a second, hornless Manda.
1969: A monster of unknown origin, Gabara, appears out of nowhere on Monster Island with no explanation available.
1970: An evolved form of Dogora, Yog, arrives on Earth and infects a cuttlefish, two rock crabs, and a Matamata turtle, turning them into Gezora, Ganimes, and Kamoebas. The poor excuse of an invasion is halted, and a theory is established that monsters such as Ebirah, Oodako, Kumonga, and Ookondoru had grown to such a size due to them ingesting deceased Dogora cells over time.
1971: Godzilla II returns to Japan and faces off against Hedorah. Hedorah is fried, though reports of another keep coming in.
1972: The Nebulans invade using their monster Gigan, as well as a once-again-under-mind-control King Ghidorah. Godzilla II and Anguirus II drive off the two monsters after the Nebulan forces on Earth are destroyed.
1973: Nuclear tests conducted to close to Monster Island tear the island apart, scattering the monsters all over. The Seatopian Empire declares war on the surface world for their reckless destruction, sending out their guardian, Megalon, as well as hijacking a human-sized toy robot, Jet Jaguar. Jet Jaguar, after being freed, flies off to what remains of Monster Island and enlists the help of Godzilla II. Gigan is once again driven off, and Megalon retreats back to his home.
-The Garoga invasion occurs, and the hero Zone Fighter appears. For reasons unknown, the invasion eerily halts without warning. It is theorized that King Ghidorah, fed up with being placed under mind control, annihilated the Garoga invaders after being set free by Zone Fighter.
1974: Anguirus II reemerges in Siberia after spending nearly a year underground and sets off to return to Japan. What appears to be Godzilla II appears at Mt. Fuji without warning and engages Anguirus II, severely injuring him, before making his way to Tokyo. The real Godzilla II appears. The one that appeared at Mt. Fuji turns out to be the cyborg, Mechagodzilla, constructed by the Simeons, a race of alien primates. King Caesar is awoken to deal with the machine, but is nearly defeated before Godzilla II returns and destroyed his mechanical doppelganger.
1975: The Simeons return, and have rebuilt Mechagodzilla. They have also gained the help of a human scientist and seize control of the aquatic dinosaur, Titanosaurus. Godzilla II, now on his own, manages defeats both monsters, and was almost killed in the effort.
1976: Monsterland is established. The monsters Manda II, Varan, and Baragon are the first to be corralled. Kamacuras and Gorosaurus follow swift.
1977: Kumonga, Ebirah, and Gabara are brought to Monsterland at the beginning of the year. Rodan III is lured there in the middle of summer, and Anguirus II just wanders onto the island like nobodies business.
1978: Oodako and Titanosaurus are finally corralled. No sign of Minilla.
- Numerous lower level monsters appear across the Western Hemisphere.
1979: A typhoon knocks out all power on Monsterland, resulting in a giant sized prison break. Humanity puts it’s faith in Godzilla II to round up the monsters.
-Godzilla II takes up residence on Monsterland.
1983: Still no sign of Minilla.
1984/5: Minilla reappears, fully grown, and is given the title of Godzilla III. Godzilla III attacks Tokyo, before being lured to Mt. Mihira and imprisoned inside the volcano.
1989: Biollante is accidentally created, and Godzilla III is unleashed by the American corporation: BioMajor. Biollante defeats Godzilla III before retreating into space.
1991: Godzilla III returns to Japan and fights an unleashed Bagan and Balkzardan.
1992: Mothra returns to do battle against her dark half, Battra, before flying off into space to deal with yet another asteroid, accidentally flying through Biollante’s spore cloud.
1993: Another Godzilla egg is discovered, and hatches into Godzilla Jr.
-A UN Mechagodzilla plan is proposed but was swiftly killed to death by outcries of ‘Too Soon!’ and ‘Have You No Shame?!’ from the populace.
-A mix of Mothra scales and Biollante spores that attached themselves to Mothra are sucked into a black hole and fuse with a crystalline organism, before being shot out of a white hole. SpaceGodzilla is born.
1994: The UN finally develops a Mecha unit to deal with Godzilla III. The Mecha unit is dubbed M.O.G.U.E.R.A. SpaceGodzilla arrives on Earth, attacks Godzilla III, and kidnaps Junior. SpaceGodzilla trashes M.O.G.U.E.R.A. and is killed by Godzilla III.
1995: The Oxygen Destroyer finally comes back to bite Japan in the ass with the creation of Destoroyah! Junior is seemingly killed, and Godzilla III is pushed to critical levels. Destoroyah is killed by the JSSDF, while Godzilla III dies in a meltdown. Junior is discovered to be alive and is brought to Monsterland, where he is adopted by Godzilla II
1996: Mothra returns to Earth to find a logging company has unleashed Desghidorah. As the aged Mothra proves to be no match against King Ghidorah’s eldest spawn, Mothra’s egg prematurely hatches, giving birth to Mothra Leo. Mothra is forced to grab her son and retreat, and soon dies. Mothra Leo soon grows into an adult, and proceeds to whoop Desghidorah’s rear end into submission, when he is sealed up once again.
1997: Nilai Kanai’s attempt at pollution control, Dagahra, awakens from his eon’s long slumber. Mothra Leo is driven to the brink in order to defeat him.
1998: King Ghidorah returns to Earth once again, and to prove he means serious business, he goes after the human children. Mothra Leo is forced to break the space-time continuum in hopes of destroying him, but to no avail. He merely manages to drive off the space hydra once more.
-An extremely mutated iguana appears in Manhattan. Due to the creature’s superficial resemblance to the King of The Monsters, the Americans dub the mutant: Zilla, much to Japan’s chagrin. Zilla is slain, and the nest it established is destroyed sans one egg. Egg hatches and the infant Zilla II imprints on Dr. Niko Tatopoulos. HEAT is founded. Numerous low-level monsters begin appearing across the globe. Leviathan Invasion occurs. Site: Omega is founded.
1999: Kilaak invasion occurs. Junior matures into Godzilla IV
-A meteor is hauled up from the ocean depths, where it is discovered to actually be an UFO. Orga appears and is slain by Godzilla IV.
2000: Project: Dimension Tide is green lit, and during a test fire a new Meganulon swarm appears through the created worm hole. The Meganulon soon manage to molt into Meganula. Megaguirus is born. Dimension Tide seemingly destroys both Godzilla IV and Megaguirus.
2001: Godzilla V appears without warning. Mothra Leo is killed; reports of a new female Mothra are made.
2002: Project: Kiryu begins operations. Kiryu is sent to battle Godzilla V.
2003: A Kamoebas carcass washes ashore, heralding the impending return of Godzilla V. Mothra returns to aid Japan. Godzilla IV reappears…
2004: Second Xilien Invasion; Operation: Final War.
2005: The effects of King Ghidorah’s demise on Earth are finally felt. Jyarumu and Vagnosaurus are spotted in the Bering Sea. Soran appears.
2006: Shiigan appears. Bagorah is driven to Earth by the Dianii aliens and is killed by Godzilla IV. Burtannus appears.
2007: Tricephalon appears and is slain by Godzilla V. Barugaron is drawn to Earth by the blood scent of Godzilla; is killed by Godzilla II. Obsidius and Krystalak appear; are destroyed by Godzilla IV.
2008: Dogolas appears.
*EDIT: Fixed numerous errors that went unnoticed before posting*








