It turned out this started with the rise of Godon and not with the arrival of the new folks. Oh well, the boundaries are blurry anyway and in the history of Ynev few hundred years don't really matter.
I'll try to keep this short.

Not many important events happen during the centuries pre-Pyarron.
Four states was created in the North on the same area where Dawa lay: Erigow and the Northern Three (Eren, Gianag, Haonwell). All four are principalities (actually Erigow is Grand Duchy) and have typical European feudal society, economy and culture. Their population has two components: the autochton folks and some others, called Ervs, who arrived from the west (which makes no sense so I just consider them among those who arrived through portals). Two notable things: Erigow's capital (she has the same name) was founded over the old Kyrian capital, Enrawell, and originally these states was parts of a kingdom, they went separate ways much later, but as I said I'll try to keep this simple.
In the South the castle of Shadon was built by Godon, this will be the seat of the king of Shadon after Godon fall and a new state emerges. More later.

A bunch of adventuring knights from Godon settled in the valley of the river Dorlan, they did chivalric tasks, defended the needy, freed kidnapped princesses, saved cats stuck on trees and such. The good folks in that area preferred to set up their tents beneath the protecting shadow of the knights' HQ, and soon a small town started to shape, they named it Pyarron.
Then a group of gods contacted one of them, a dude named Selmo and told him... I dunno maybe they said they are the good guys or something but it must have been damn convincing. They made him their prophet, told him to spread their faith and blessed him with an exceptionally long life. This is the year 0 according to the Pyar Calendar. And he did spread the Word. The stuff these gods said to him was very acceptable for all kinds of people and the new faith spread fast. Fastish. 1km/year.
These gods already existed under different names and they had no connection to each other. It seems they made an alliance and the new Pyarronite faith sold them as a family of gods, similar to the Greek or Roman ones. Let's list these gods, and say a few words about them:
Adron - god of magic and light
Alborne - goddess of songs, music, legends, feasts and celebrations
Antoh - goddess of sea and storms
Arel - goddess of fight, struggle, nature, bravery, obstinacy
Darton - god of the dead, death, (dark) jokes, as you guessed he's the most coolest of this bunch
Della - goddess of arts
Dreina - goddess of wealth, order, true rulers, fidelity