The defeat of the Naga and conquest of the South by the God-King marked the beginning of mortal civilization and the rise of the first kingdom. But though the serpents were driven back beyond the great river, their threat to the mortal realms was never completely broken. It is by the might of the God-King and his royal guard that the southern realms are being kept safe and their people are protected from being enslaved or devoured.
With the divine power of the God-King, no serpent armies have crossed the river in living memory, but in the jungles beyond the eternal war has never ceased. The sacred duty of protecting the realms of mortals from the snakes is given to the royal guard, masked soldiers of the greatest skill and might who hail exclusively from an ancient caste of warriors fanatically devoted to the service to the God-King. Regular soldiers are given the dreaded assignment of guarding the river and prevent the crossing of raiding parties that managed to slip by the royal guard engaging the main armies of the serpents in battle. Typically these consists of barbarian warriors from deeper within the jungles who have become thralls enslaved by the insidious magic of the snakes, but all people have heard stories of patrols that were ambushed by naga warriors and sorcerers and slain or devoured to the last man.
Soldiers of the God-King patrol the northern bank of the great river to prevent anyone but the royal guard from crossing, to prevent any snake cultists from revealing information about their enemies to their terrible masters. And no lone wanderers or stragglers are allowed to return, as the serpents use their dark magic to enslave the minds of prisoners and send them back as spies and agents to spread false rumors and trick the watchful guardians to become complacent and underestimate the threat of another naga army crossing the river to retake their ancient lands.
Since the day the God-King ascended to his reign over the people of the southern realms, he has led them into battle against the serpents and to victory. And it is by his might alone and the valiant struggle of the eternal war that the lands of mortals are kept safe, and for the people of the south, this alone is proof enough of his divinity.