Many years ago, a group of Echidnas departed from the Echidna city of Albion in search of new adventures and land. The pioneers first came to a continent in the Southern Hemisphere where they began to colonize. Shortly afterwards however they discovered they had attempted to settle in the Mysterious Cat Country. Soon, the Cat People and the Echidna settlers became engaged in a war. The Knuckles Tribe wanted to remain and fight for their new land, while the scientific elite and intellectuals wanted no part of the conflict. Thus, the latter left on their ships to find a new land, while the Knuckles Tribe remained behind to continue their war with the Cat People. The scientists travelled to the continent of Downunda where they began colonization and the created Echidnaopolis.
After years of development, Echidnaopolis was one of the most developed cities on the planet. While two of their top scientists, Jordann and Kayla-La, were exploring and charting the stars, they came across the discovery of a massive comet on its way to Mobius and on a direct collision course for Echidnaopolis. The two brilliant scientists proposed that they lift their city airborne using the power of numerous Chaos Emeralds to avoid destruction. The Echidnas proceeded to launch a massive excavation of the planet in search of the Chaos Emeralds. Once they had obtained enough, they placed them within the deep caverns below the city. Meanwhile, the Fire Ants dug their way deep under the city until it was no longer connected to the planet's surface. The power of the Chaos Emeralds, resonating through the city's infrastructure, Echidnaopolis was lifted into the sky, just before the comet struck the planet.
The society on Echidnaopolis suffered another, much larger schism of its population over 600 years ago, which stemmed from the decision of the Echidna Council (particularly Menthor, the High Councilor at the time) to deny Dimitri and Edmund's plan to restore Angel Island to its original site on Mobius. When Dimitri took matters into his own hand and attempted to use the Chaos Syphon to drain the power of the Chaos Emeralds so the Island would slowly descend onto Mobius, the power was sapped into him. Despite the immense power he obtained, he was defeated by his brother Edmund, with assistance from the fire ants. Because the use of technology nearly resulted in the destruction of their civilization, the Echidna Council then deemed technology banned.
However, Dimitri's son, Menniker decided to follow in his father's footsteps. He created the Dark Legion, a technocratic group of Echidnas loyal to Dimitri's cause of restoring the Island to Mobius, as well as maintaining technology in their society-which became a warring faction with the rest of the society. Since then, both the Dark Legion and the rest of the Echidnas in Echidnaopolis have been in conflict.
In addition to the Dark Legion, which managed to breach the dimensional barrier numerous times and attack Echidnaopolis, the Guardians had to contend with the other native species on the Floating Island, the Dingoes. A militaristic and brutal race, the Dingoes nearly wiped out Echidnaopolis via nuclear strike, but were stopped by the current Guardian at the time, Hawking. To prevent all life on the island from dying to the radiation, he transported Echidnaopolis to its own pocket zone, and the Dingoes to another. He then began the tedious task of restoring the island to its former state.
DestructionEchidnaopolis was destroyed when the Dingoes joined forces with Dr. Eggman and took over, overwhelming the Echidnas and forcing them into concentration camps as well as killing off 90% percent of them. The few survivors were later liberated by the Chaotix and relocated to a village, but with most of the Brotherhood gone they were ill-equipped to defend themselves. Locke the Echidna, Guardian and father of Knuckles, defended them briefly before turning the position over to Dr. Finitevus, which allowed him to go off in search of his predecessors. Finitevus and his Destructix minions defended the former residents of Echidnaopolis briefly, until the new Enerjak came to power. The demigod then transported them to Albion with the rest of the Echidnas in hopes of rebuilding their ravaged species.
Knuckles the Echidna
Espio the Chameleon
Mighty the Armadillo
Vector the Crocodile