Settra the Imperishable was a king of Khemri. Born in a time when Nehekhara was plagued by drought, famine, disease and war he was determined to lead his people to greatness. He was an arrogant, vain and tyrannical ruler, but also especially devout and instigated the building of many great temples so as to earn the favour of the gods. On the first anniversary of his coronation he beseeched the gods to restore Khemri to it's former glory and to give him the strength to unite all of Nehekhara under his rule. He sacrificed his own children in a grand ritual to demonstrate his dedication, commitment and worth. The gods were pleased and the when the Great Mortis River flooded for the first time in decades Khemri was purged of it's sickness and collected a harvest of unparalleled size. Seeing this as evidence that he was the chosen of the gods Settra became the first Priest King of Nehekhara.
Between the great legions of Khemri and Settra's own ruthless military genius he swiftly conquered the other cities and became the first king to unite all of Nehekhara under his rule. He established an empire and instated various leaders in other cities to provide tribute. As the undisputed king of both Khemri and Nekhara as a whole he was adored by his people as the land entered a golden age. Still not content, his armies set sail in mighty war fleets and conquered lands across the globe, with much treasure and slaves brought back to labour on the great monuments that Settra commanded built to glory both the gods and himself.
For all his conquests, he was still frustrated. He knew that there were still lands out there to claim, more than could ever be reached in a single lifetime and also that one day death would take away from all he had created. In his supreme arrogance he vowed that the grave would never have him, and that he would cheat death. He set his greatest, wisest and most powerful priests on the mission to find the solution to this. This group would become the Mortuary Cult a priesthood dedicated, not to any god, but rather to discover a way to cheat death.
The priests searched for years and discovered many incredible things, including the art of mummification, but could not find what Settra sought. He lived far beyond any mortal span thanks to their arts, but he could not be kept alive indefinitely. On his death bed, the priests promised that one day he would return and rule over another golden age, a paradise. He died with a curse on his lips and his body interred in a great pyramid of unsurpassed majesty and bound with the mightiest incantations of power and preservation until his appointed day of awakening. He was succeeded by King Ahtaf I.
Nagash's Great Ritual, cast over the entire of Nehekhara, caused countless dead rise from the graves bound to the will of Nagash. However, with the Great Necromancer's assassination at the hands of Alcadizaar they were left with no guiding force. Interestingly the hundreds of risen Priest Kings found they had been brought back with their minds, memories and willpower intact- though without the golden bodies and a paradise to rule they had been promised. Immediately they went to war with each other, various dynasties and even families battling for control of their tomb cities. Desperate to stop these Tomb Kings from finishing the work Nagash started Khatep, Grand Hierophant of the Mortuary Cult and oldest, wisest and most poweful of their kind breeched the tomb of Settra so he could restore order.
In death Settra was no less mighty than in life and he quickly dominated or destroyed all who would challenge his absolute authority. Even the so-called Liche King Arkhan the Black was forced to flee before him. After taking control he summoned his priest to explain what had happened. Hearing the tale of Nagash and the failure of his cult to deliver on their promises of an eternal golden age Settra cast his priests away, knowing that they had lied to him and kept most of their powers to, and for, themselves. He vowed to restore his empire to it's former glory and create the paradise on earth he so desired himself.
He ordered many Tomb Kings to return to their chambers and await the call to return to life, for they would only raise unrest and disturb the peace. He commanded that contact with the living be forbidden (unless he commanded it himself of course) and thereafter the Tomb Kings mostly only rode to war in their own defense or to reclaim relics stolen by treasure hunters from around the world.