It is led by someone named Zarakh Om Barya. One could attribute his current hegemony on the southern region as a product of luck
He is one of the general of the southern borders as such he had the advantage since he was already on the south when it all goes down
He also knows how to best use the opportunity that he had
When he receives the news of the fall of the Capital, with his connection he had gathered the generals of the south in a meeting on top of a small mountain called Erciyes mountain.
He gathered them and told his plan to take back the southern region from Greater Veranis and reestablish back their kingdom
There were some generals that did not want to join in and they were all killed by Zarakh. The other then obey him and he created the Erciyes army
The Erciyes name was taken from the name of the mountain.