History of Threia

Note: This is just a shotgun blast of ideas meant to get things down on paper so I can better visualize the timeline

The Exodus
With their homeworld on the brink of death, humanity reaches out to the stars in search of a new planet to call home.

Each of the world governments has a plan for the furtherance of their ideals. Some send massive vessels into the heavens hoping that at least one of these generational craft might find a suitable home and that their lineage would not die out.

While the rest of world desperately abandons their homes for sub-light space craft an enclave of more archaic-minded individuals seeks a more immediate solution.

The Rei
Masters of artificy, theurgy and all other manners of arcane discipline, The Rei is an organization of arcanists and mages dedicated to the study and regulation of their craft. For centuries they have secretly planned for the inevitable and in the final years perfect their method of exodus.

Through the folding of space and time they are able to establish a link with world millions of light years away that offers a hospitable alternative to their dying world. In the final months they send scouting parties across the vast voids of intergalactic space, establishing a suitable landing site to bring over the entirety of their arcology and the thousands of men, women and children of The Rei.

But in the final moments when the arc and all of it's inhabitants is to be transferred across the void, there is a temporal slip. A fraction of a decimal misplaced in the massive arcanical matrix causes thousands of years of temporal drift in a split second. The flatted landing space, perfectly surveyed and sculpted before hand to accept the sudden presence of the arcology, shifts under thousands of years of erosion. The hundreds of scouts, surveyors, theurgists and artificers sent ahead to prepare for the arcology's arrival are effectively stranded. And in that millenial slip those hundreds grow to millions. Kingdoms rise and war. Nations succumb to plague. Cultures form and are forgotten. Much that was lost and forgotten is rediscovered and lost again.

Then in the middle centuries of the second age, the arcology arrives. The massive tower of sleekly intertwined geometry arrives amidst a dense forest. Where there should have been flat plains of scrub and grass there are now twisted hills of towering redwood. The arrival is cataclysmic. The resulting sudden and violent sub-atomic displacement of matter levels hundreds of miles of forest and nearby villages and towns and ignites a conflagration that would burn for years. The resulting seismic event forms a half mile deep impact crater, throwing enough debris into orbit to cause a world-wide climate shift as it burns falling back to the surface. The Arcology survives the intitial blast, having not fully phased into true existence, but the resulting half-mile fall leaves the tower in ruins at the base of the crater. There are only dozens of survivors.

The Cataclysm
The results of the Arc's arrival is felt around the world. Locally, the seismic after shocks are devastating. The debris from the impact burns as it renters the atmosphere and the planet is enshrouded in a conflagration that nearly scours all life from Threia.

Not all was lost. For many of the mountain holds of the DuaKhir held fast against the shudderings of Threia and the high peaks surrounding their vales held the winds of fire at bay. Many other small enclaves of humanity survived as well, for fate had placed them in protected climate shadows cast by mountain, sea or open mesa.