"Upon the empty throne, the empty king is sat.
Before, in seat so plain,
The Steward he quietly waits, a king in all but name."
The disappearance of Alexander was so sudden and unexpected, so inconceivable that no plan was available for what should be done in such an event. The Hegèmon was - and his loyal supporters insist, still is - immortal and practically invulnerable. The concept of succession had just never come up.
Though none of Alexander's closest friends and advisors could decide what to do, they agreed on one thing; tell no-one. The Hegèmon was probably only gone for a short spell, something had come up or he needed a moment to adequately mourn his friend, Jeshua, who had recently been murdered in Jerusalem. He would be back in no time!
A year passed, and then five years. The Senate were getting suspicious that the Hegèmon did not attend meetings but sent a proxy (at first Kalliades, then Lupernikes). Eventually Kalliades saw that something had to be done and he went to the only place he could think of to find an answer, he went to the Dragon.
What she told him comforted and disturbed him equally; she knew Alexander was alive but could say neither where he was or when he would return. The Empyraeum might remain headless for quite some time yet and, with such an empire, the absence of a leader could mean no less than total dissolution.
Unless someone almost as worthy, someone also immortal and possessed of the faculties she had given them could step into the breach and plug it, at least for a time.
Kalliades stepped up as the first Steward of the Empyraeum and a story was passed around that Alexander had been called away on some vital mission regarding the future safety of the human race itself. One century at a time, a new Steward was chosen from within the Dracograth and, once for the last and longest serving Steward, from the Kalshodar.
Lupernikes surprised everyone, perhaps even himself, with his innovative and inspired ability to govern. Under his brilliant Stewardship, the Empyraeum grew stronger, developed ties with the other nations of Gaia, and reached out to the very stars themselves.
It was also under his Stewardship that The Council raised its ugly head and the sour odour of civil war insinuated itself into the air. The last Steward quietly withdrew and took Kalshodar and Dracograth with him in EA 1858.