With the expansion of Great Lixis in the Third Age most Aer O-Erken clans travel around the World Spine to the west, only returning with the fall of Great Lixis and most of the other eastern human kingdoms.
With the quickly growing expansion of Great Lixis in the Third Age the Aer O-Erken further retreat into the Beastlands and further west around the World Spine. Only few, but enlarged Aer O-Erken clans remain in East Andaria in the Marauder Beastlands. Only with the destruction of Great Lixis and the fall of most of the eastern human kingdoms the Aer O-Erken return to East Andaria, claiming the vast and emptied steppes.