Of that epoch known by the Nemedian Chronicles as the Pre-Cataclysmic Age, little is known except the latter part, and that is veiled in the mists of legend.
Known history begins with the waning of the civilization of the main, or Thurian continent… a civilization dominated by the kingdoms of Ramelia, Valusia, Verulia, Grondar, Thule and Commoria. These people spoke a similar language, suggesting a common origin. Though they don’t seem to be in agreement. The barbarians of the age were the Picts, who lived on islands far out on the Western Ocean, the Atlanteans, who dwelt on a small continent between the Pictish islands and the Thurian continent, and the Lemurians, who inhabited a chain of large islands in the Eastern Hemisphere. There were vast regions of unexplored land, the civilized kingdoms, though enormous, occupied a relatively small portion of the whole planet. Valusia was the westernmost kingdom of the Thurian continent: her capital, the City of Wonders, was the marvel of her age. Grondar, whose people were less highly cultured than those of the other kingdoms, was the easternmost land. Among the less arid stretches of desert East of Grondar, in the serpent-infested jungles and among the snow-perched mountains, there lived scattered clans and tribes of primitive savages.
On the Far Eastern shores of the Thurian continent lived another race… human, but mysterious and non-Thurian, with which the Lemurians from time to time came in contact. They apparently came from a shadowy and nameless continent lying somewhere east of the Lemurian islands. Far to the South, there was a second mysterious civilization, unconnected with the Thurian culture and apparently pre-human in its nature.
The Thurian civilization was crumbling, their armies were composed largely of barbarian mercenaries. Picts, Atlanteans and Lemurians were their generals, their statesmen and often, their kings. Of the bickering of the kingdoms and wars between Valusia and Commoria, as well as the conquests by which the Atlanteans founded a kingdom on the mainland… there are more legends than accurate history.
Then the cataclysm rocked the world. Atlantis and Lemuria sank, the Pictish islands were heaved up to form the mountain peaks of a new continent, while sections of the Thurian continent vanished under the waves or sinking, forming great inland lakes and seas. Volcanoes broke forth and terrific earthquakes shook down the shining cities of the empires. Whole nations were blotted out and the face of the world was forever changed.
Several countries sink into the sea, others rise from it, and the rest is devastated by earthquakes and volcanoes. Civilization is destroyed and the survivors attempt to build a new culture but warfare and a Lesser Cataclysm strike, creating the Hyborian Vilayet Sea and destroying any last remnants of Thurian society.