Genetic and linguistic evidence has made it very clear that both the Serevan and Erinoran peoples are descended from a single migrant population. This Paleo-Serevo-Erinoran people are believed to have arrived in the relatively isolated Erinoran basin around 15,000 BCE.  Archaeological and genetic evidence is strongly in favour of a migration from the North Eastern Continent via the Rainbow Islands, which in turn suggests a culture already used to travelling via the sea, something which would continue to be of great importance to the Serevan people groups.

Whilst there is evidence of genetic relations to the PSE peoples in more northerly lands, and even some suggestion that they may have reached further south into the basin currently occupied by the Frost Empire, it seems that, either through the impacts of colonisation, disease, natural disasters, or competition with earlier and later migrant populations, they were not very successful in any of these regions.  Consequently, the surviving Serevo-Erinorans are to be found almost exclusively in the Erinoran basin.

Diversification of the Serevo-Erinoran peoples seems to have happened relatively early on, with archaeological evidence supporting the theory that the island of Sereva had begun to be settled as early as 14,000 BCE and the fossil record suggests that there may have been major periods of conflict between those living on the coast and those who had settled in the rainforest. 

Evidence of agriculture and even silviculture appears in the rainforest, particularly near the source of the Qassar Syiranad, at around 7,000 to 6,000 BCE, with the first evidence of what could be termed conventional civilisation, with large settlements, complex structures and religious practises, appearing at around 3,500 BCE. It is theorised that the extensive Erinoran rainforest was, in fact  heavily managed by the human population for thousands of years by this point, rather than being the pristine wilderness it is often supposed to be.

The coastal populations were rather slower at developing the trappings of civilisation, most probably due to the somewhat easier coastal life, with abundant fish stocks and access to agricultural land nearby. Whilst it is clear the early Serevans were skilled mariners, there is little evidence of anything more than extremely primitive settlements and a semi-nomadic lifestyle until nearly 1,000 BCE, which may explain why they have always been the underdogs of Erinoran history.

Civilisation was also stirring in the mountains and, although it lagged a little behind the rainforest civilisation, it was to be the spark of inspiration that would create the first truly great Erinoran culture.