Sonic Chronology:
History of Mobius
(Mobian Era 0-3199)

The early Mobian Era:

* The Hidden Palace is built in the Hidden Palace Zone of the Island that will one day become Angel Island. A tapestry is woven and hung there depicting Super Sonic fighting Robotnik. The identities of those responsible are lost to time.
-- Sonic 139. "Thousands" of years ago. This may have been earlier, during the reign of Ixus, or as late as during the height of Albion's World-spanning civilization.

* Ixus the Mammoth, or “Ixus Mogul”, began practicing with his powers, slowly mastering Elemental and Crystal magic.
-- Sonic 163: “Darkest Storm” Part 2

* The Echidna are the first Mobian Race to develop an organized civilization. The heart of their civilization is the Island of Albion.
-- “Tales of the Great War” and other stories. Knuckles 10 placed the civilizations rise and fall around the year 2000, but was mostly referring to it's rise and fall as a technological world power. It must have existed in a more primitive state prior to that, as in Sonic 163: “Darkest Storm” Part 2, we learn that the Albion Knights battled the Order of Ixus “thousands” of years ago.

*c. 1000: The Mammoth Ixus Mogul founds the Order of Ixus. They make a bid for world conquest, but are stopped in a war with the Echidna Albion Knights of Aurora. Ixus escapes and goes into hiding. A few other members of the order also escape and go into hiding, keeping the Order running in secret for generations.
-- Sonic 163: “Darkest Storm” Part 2. “Thousands” of years ago.

*c 1500 - 2000 -- The "Echidnas" build an industrial civilization based on that of the pre-Fury humans. They even rediscover space travel.
Knuckles 12. Gala-Na referred to the rise and fall of the first Echidna civilization as having occurred "over a thousand years ago". I would place it closer to 2235, except in Knuckles 10 Athair mentioned a “Day of Fury” “twelve hundred years” ago, and implied it was caused by pollution. As Echidnas were the first industrial civilization in the Mobian Era, they must have been responsible for the Day of Fury Athair mentioned, and thus they must have started their civilization prior to 2035.

*The (Third & Latest) Day of Fury-- 2035 ME-- Pollution from the rise of the Echidna Civilization led to environmental disaster. This event led to the near collapse of Echidna civilization. The few remaining Echidnas retreated to the island of Albion, and secluded themselves from the rest of the world.
Knuckles 10 & 12. Athair said the latest Day of Fury occurred twelve hundred years prior, "under similar conditions" [to Robotnik’s pollution]. I have chosen to assume the Day of Fury was what brought Echidna civilization to its' end.

*Some centuries after the Echidnas retreated to Albion, a small group of more adventurous Echidnas, led by the warrior Knuckles Clan, departed Albion to seek a new home.
Knuckles 12; Sonic 82—"Door to the Past"

*The visionary Alexander Acorn founds a multi-racial town that will one day become Mobotropolis. The Echidna wanderers were in the region at the time, but chose not to join. Alexander is crowned King, founding the Kingdom of Acorn. Alexander also bonds with the Source of All at some point, starting a tradition that will last until Robotnik's coup.
--Sonic 71- "Tales of the Great War" Prologue. Dating is uncertain; that the wandering Echidnas were the group that would eventually make it to Angel Island is speculation. It could just have easily been Echidnas before Albion became powerful, or the Forgotten Tribe after the rise of the Floating Island. That Alexander bonded with the Source was revealed in Sonic 162: Darkest Storm Part 1.

*The Echidnas led by the Knuckles Clan settle down in the Mysterious Cat Country. Soon after this, the Echidna colonists came into conflict with the Cat people. The Knuckles Clan decided to fight for their new home, but the scientists wanted no part of this, and departed to continue their explorations.

The leader of the Knuckles clan, Pachamac, and his daughter, Tikal, discovered the Mystic Ruins, wherein lived the mysterious "Chao". Tikal befriended the Chao, as well as the water-spirit Chaos. However, the war with the Cat people went badly, and, seeking the power to defeat them, Pachamac attempted to take the seven magical "Super" Chaos Emeralds from the Mystic Ruins. Chaos would not stand for this, and reacted violently, brining an end to the entire Clan, with the exception of Tikal.

Eventually, Chaos became corrupt with power, and to stop him, the seven lead Chao bonded with the seven Emeralds to create a prison for Chaos—a huge black Emerald. To seal Chaos within this prison, Tikal herself bonded with the black emerald, imprisoning not only Chaos, but herself in the emerald…

Sonic 82—"Door to the Past"

2635-- The Rise of the Floating Island

The Echidna scientists Kayla-La and Jor-Dann discover a Great White Comet on a trajectory that will cause it to impact Echidnaopolis.

Kayla-La proposes a daring plan – to use the power of 12 Chaos Emeralds, placed within the crystalline chamber beneath the city, to lift the island Echidnaopolis is on out of the river it is in and into the sky.

The holy-man Arakkis objects to this plan, but the council sides with Kayla-la. Arakkis and his followers depart Echidnaopolis in search of a new home, while the remaining Echidnas scour Downunda for Chaos Emeralds.

The island's fire-ant population chews a crack in he bedrock of the island so the island can be separated from the rock below it. The Echidnas place 12 Chaos Emeralds within the crystalline caverns below the city, and the Island rises into the sky.

The comet impacts where the Island had been, creating the Downunda Crater.
--Sonic 34- "A Sense of History" Part One; Knuckles mini-series #2; Knuckles 10

*The history of the Forgotten Tribe
--Knuckles 10

*The Nerbs begin living underground.
-- “Centuries” before Sonic 10: “The Revenge of the Nerbs”

The Twenty-Ninth Century:

2858-- Day 271: The Birth of Edmund and Dimitri to the House of Kayla-la
--Sonic 105- Sega Data File #6

2864 -- The Royal Acorn Family begins use of its Ceremonial Acorn
--Sonic 18- "In the Still of the Night". Said to have been in use for 12 generations; date based on an average generation of 30 years.

2874-- The Origin of Enerjak

Echidna scientists Edmund and Dimitri propose a plan to drain the energies of the Chaos emeralds and rejoin the Island with the land. Prior to their meeting with the Council to decide on the matter, Dimitri tries to convince Councilman Menthor to support him, but is unsuccessful.

The council denies the petition on account of the procedure being too much of a risk.

Dimitri defies the council's orders and uses the Chaos Siphon. The siphon has no effect on the Island's altitude, but it does destroy 11 of the 12 Emeralds and transfer their power into Dimitri, turning him into “Enerjak”.

Enerjak uses his powers to create a dark tower over the city. He conquers the city and prepares to conquer the world. He is stopped by the Island's Fire Ants, who undermine his tower and collapse it upon him.

In the aftermath of this disaster, Echidna society renounces technology, and appoints Edmund as the first guardian of the Floating Island. They plan on burying their technology in an underground city in the shadow of the remains of Dimitri's Tower. The remains of Dimitri's Tower become known as “Mount Fate”.
--Sonic 35- "A Sense of History" Part 2, Sonic 36- "A Sense of History" Part 3, Knuckles Dark Legion 1, Knuckles 22.

*The Origin of the Dark Legion

Dimitri's son, Menniker, witnesses a burst of emerald light from Mount Fate. He interprets this as a sign from his father to continue what Dimitri had started. In response to this, he founds the Dark Legion.
--Knuckles Dark Legion Trilogy

*The First Passing of the Mantle

The Fire Ant Queen appoint the fire ant Christopholes as a guide to the Island's Guardian, Edmund.

Not long after this, Edmund's son Steppenwolf investigates a Dark Legion gathering. Steppenwolf is discovered, and flees. Edmund comes to his rescue, but is killed by the Dark Legion.

Christopholes becomes Steppenwolf's guide and helps him assume the mantle of Guardian.

-- Knuckles Dark Legion #2

The Thirty-First Century:

3035-- Hawking Vs the Dingoes

The current guardian of the Floating Island, Hawking, discovers some Dingoes stealing nuclear weapons from an Echidna Storage Depot. Fearing the results of a nuclear attack, Hawking uses some of Dimitri's theories to build a Hyper Zone Projector. The expected attack comes, and Hawking uses the HZP to transport Echidnaopolis, the Dingo City, and many of the island's other inhabitants into alternate dimensional “Pocket Zones”. The nuclear explosion kills all other life on the Island, and renders it uninhabitable for centuries.
--Knuckles 5

3055: Tobor's Tale
--Knuckles 17

The Thirty-Second Century:

3108-- Kragok and Lien-Da born
--Super Special 11- "Shadows". Date based on dates within "Shadows", Julie-Su's age as 15 in 3236 (Sonic 102- "Data File 4"), and Twilight Zone time as 4 times slower than normal (Knuckles 18).

3135-- The first animals are restored to the Floating Island
--Knuckles 5

3140-- Luger and the Dark Legion exit and return to the Twilight Zone
--Super Special 11- "Shadows". 8 years, Twilight time, after the birth of Kragok and Lien-Da. Note: the proximity of this event to the nuclear catastrophe on the Floating Island raises the possibility that Merin-Da's illness may have been related.

314x?-- Athair Born?
--Knuckles 11

3172-- Luger and Mari-Su are married.
--Super Special 11- "Shadows". 16 years, Twilight time, after the birth of Kragok and Lien-Da.

317x?-- Sabre born?
--Knuckles 11

3176-- Day 277: Julie-Su born
--Based on dates in Super Special 11-"Shadows" and on Twilight Zone years being equivalent to 4 years of Mobian Time. Day of the Year from Sonic 102- "Data File 4" (which gives her birth-date as 3221, clearly impossible if she spent most of her life in the Twilight Zone).

3176 - 319x-- Julie-Su's childhood
--Super Special 11- "Shadows"

318x?-- Sabre assumes Guardianship.
--Knuckles 10

3186 – The Origin of Shadow, Part One
Maria Kintobor develops a rare neuro-immuno-deficiency syndrome. Her grandfather, Doctor Gerald, begins working on a project to develop a cure. He plans to genetically engineer a Mobian Hedgehog to produce a chemical that will heal a victim of NIDS. He constructs a space-station, the Ark, to serve as his lab.
-- Presumably a few years before the actual creation of Shadow. Exact date is arbitrary. I know the family name is “Robotnik” in the games, but in the comics Gerald would seem to be Dr. Gerald's last name, and both Maria and Robotnik apparently had the last name Kintobor at birth – though I've seen Maria called Maria Robotnik even in the comic at times.

3187 - Dr. Gerald tests his theories by creating the “Bio-Lizard”. The experiment is considered a failure.
-- Sometime before he created Shadow. I don't know if it was before or after he contacted Black Doom, so I have chosen to place it before.

3188 - The Origin of Shadow, Part Two
Dr. Gerald runs into a dead end in his research, and enlists the aid of an alien known as Black Doom. Doom granted the engineered hedgehog Chaos Control, and made other modifications that would make “Shadow” a living weapon. Created as both the greatest force for both peace and war, Shadow became known as “the Ultimate Life-form”.
Black Doom promised to return in fifty years with his Black Arms army to pick up his weapon and conquer the planet.
-- Sonic 171: “I AM”. Said to be fifty years before the present.

3189-- Day 233: Julian Kintobor, Maria's half-brother, born.
-- Sonic 108- "Data File9"

* The Origin of Shadow, Part Three:
Shadow the Hedgehog is completed. However, he will need some final treatments before he can produce a cure for Maria. While they are waiting for this, Shadow and Maria become fast friends.
-- Some time before “As The Shadow Awakes”. In that we see Shadow in a tube, but he must have been able to get out of that tube before hand to have made friends with Maria.

3190 – Sonic 86: “As The Shadow Awakes”
Even as Doctor Gerald gives Shadow the treatment that will allow him to cure Maria, GUN arrives at the Ark, wanting Shadow for themselves. GUN attempts to capture Dr. Gerald, and Maria is killed. Shadow's escape pod is found by GUN, and Shadow is put into suspended animation. Dr. Gerald is forced to work for GUN, but secretly leaves an evil surprise for them – a program designed to use the Eclipse Cannon on the Ark to destroy the world. He also fails to warn anyone about the coming arrival of the Black Arms.
-- In 158: “System Reconfiguration”, Eggman claimed to have been an infant at the time of Maria's death. If we believe the date of birth given in Robotnik's data file, Maria's death must be after 233/3189.