The Elves, Janns and Amunds fought a destructive war when the Amund god Amhe-Ramun tried to influence directly the events on Ynev. The Janns destroyed his manifestation but the war also obliterated the forests south of the Sheral and turned it into that strange desert. The Amunds retreated into their labyrinths and temples located deep in the desert, the Janns were decimated, lots of Elves lost their mind and become loony lonesome Sand-Elves, the rest withdrew into their forests.
Especially after the fall of the Auld-Tree the magic sipped out of the world slowly, the Web of Mana formed around the globe.
The Aquirs went to hiding too. Some subspecies of them into the oceans but the "regular" ones burrowed their new cribs around high concentrations of magic. One such place was in Krán (South Ynev), where they gathered around the veins of living metal (also called blacksteel, but it might be an entirely different material which also can be mined only in Krán), the other one is in the North, in the mountains of Ediomad, among the roots of the Auld-Tree.
Most likely the first Humans saw the daylight first in those days. And maybe the Orcs and Goblins were created by Orwella at that time.
The higher-beings - now can be called gods - made a pact that they will stay away from the Primary Material Plane and they only try to shape the fate of the world via their followers. This is called the Ancient Treaty. The gods from now on can be considered the same in their essence, they only got different names in later ages.

Now I have to interject few things.
The Nine created a bunch of Planes, elvenoids exists on three: Material (body), Astral (emotions), Mental (conscious thoughts) Planes. Other different Planes were created as well and the gods made their home there. For example the Three Headed God, Tharr's plane is Lyndigass, the Shandin is the name of Darton's Plane, who is the God of Death and Jokes, and Noir owns Antiss, the Dreamworld (World of Mirrors).
The gods themselves are mortal, their power depends on the number and dedication of their followers. Some gods faded away and other beings elevated among the gods.
All right.