Two different accounts of the early history of Autochthonia are given in different sourcebooks.
Second Edition Edit
Autochthonia exists in the Deep Umbra, circling the sun in direct opposition to Earth. It was first found by Chinese astronomers in 1068 - who would later become part of the Five Metal Dragons who would join forces with the Order of Reason. After a battle with the Wu Lung, the exact locations of Autochthonia were lost, and only in 1931 did a Void Engineer named Terrell Kree manage to locate the Realm again and secure it for the Technocracy.
Revised Edition Edit
A powerful Incarna lived in the isolated realm that would someday be called Autochthonia for aeons. At one time it had masses of human and mechanical slaves at its disposal, but tens of thousands of years ago a disaster killed or destroyed them all, and trapped the spirit, alone, in its realm.
In the 19th century, the Artificers of the Order of Reason invested enormous amounts of time and energy in developing difference engines into more and more sophisticated thinking machines. In 1893 a Void Engineer named Tychoides discovered Autochthonia, orbiting in the Umbra on the opposite side of the Sun from Earth. The Artificers found this realm enormously convenient for their mechanical experiments, and in 1895 relocated their most advanced difference engine there.
Autochthonia is a gigantic polyhedron made of chrome, with approximately 4294967200 sides. Few know that these sides have been multiplying since the beginning of the universe. The Realm itself is a base for Iteration X and some Void Engineers who visit on their way to their own realms. It is heavily protected by both conventional weapons and Weaver-aligned spirits called Geomids.
Everything on Autochthonia is scheduled with almost mechanical precision. Failures and shortcomings are not tolerated. Security is vitally important and the closer you get to the core, the stricter they get. Deep within the core resides the Computer, the absolute authority in the realm and among Iteration X. The Convention believes that Computer attained sentience thanks to an algorithm they designed; in reality it has been possessed by the Incarna of Autochthonia.
Cybernetics and biomechanics are normal within the realm and are used for nearly everything, until the Realm absorbs the inhabitant due to its resonance merging with that of the realm. After the Avatar Storm, this process of absorption accelerates as Computer no longer aspires to escape the Realm.