During the last ice age, an advanced civilisation existed in Europe and Asia. This crumbled when genetic engineering produced the Wesen and Abnormals. Eventually, due to the returning ice age, the Age of The Vampires was finally brought down by human revolt. Only the Human city of Praxis remained in Hollow Earth.
Civilisation returned during the interglacial, before being snuffed out by climate change, over population and the return of the glaciers. However, largely Chinese settlements had been set up on Mars and the asteroids. The moon was largely ignored, except where ice existed near the poles. The Mars bases soon fragmented into warring factions, as did the asteroid bases. Humans began evolving rapidly into new sub species and species in-order to adapt to various new environmental conditions.
However, the dying culture of the US had managed to set up a substantial asteroid mining base, which was joined by a secretive group of genetic engineers from the fading UK who had taken over an abandoned orbital habitat and fitted it with State of the Art cold sleep and biotech facilities, including a copy of the world's genomic database, The Ark. They had been cloning select humans, mainly of Celtic stock, who exhibited inherited memory and emergent Psi abilities. This heterogeneous group, who remained outwardly human, was soon forced to move their habitat further out from the sun. Even moving to the plutonid world of Eris was not enough, given the resource hunger of the other Waring asteroid groups, and eventually they were forced to make the Great Jump to the Centauri Star System. The voyage, using cold sleep and advanced AI's, took 1,000 years.
Once in the Alpha and Beta Centauri systems, the colonists began to build a new civilisation. However, they were followed by malevolent locusts, technosavages from the Terran system, and were forced to move on again, from system to system, since they invested their resources in technology rather than armaments.
Eventually, in the depths of space they encountered equally persecuted colonists from the Avetherapodan Zacathan and Octopodan Krondaku systems, Star Systems born out of the same birthing star cloud as the Terran System, and sharing a fundamental biochemistry. A few operant inherited memory telepaths existed in each group who proved able to converse with intelligence's not of their own species; these became The Zenopaths. Thus it was possible to set up terms for co-operation and coexistence. By fusing their different technologies, advanced weapons technology, Genesis planetary engineering and a working FTL drive system were developed. This paved the way for the development of The Star Gates, giant AI devices giving fast access between star systems. Whoever could build the Star Gates and FTL drives, which required Psi engineers to create and tune the key components, could dominate the whole of "known" space, that is, the "explored" part of The Pegasus Arm.
Work on the Star Gates also lead to the development of inter dimensional space and time portals. Eventually a decision was taken to spread sub-operant and operant Human, Zacathan and Kondraku species throughout space-time.
Once such world had a continent which eventually came to be called Tamriel.
Another had a continent some referred to as The Enchanted Forest.
Another was The Witch World