Commonly known as the Empire, the Tiamat Imperium is a vast, evil, militaristic state spread over numerous worlds with a complex bureaucracy largely split between the armed forces and the priesthood. Most citizens are members of one of the Five Shades of Zendikar, military alliances among Dragonborn and true dragons of the same color. The Order of Tiamat is the state religion of the empire; a priestly order of dragonborn clerics and sorcerers who lead the worship of Tiamat, the mother goddess of all dragonkind. The two factions are intertwined, as the high priests of the Order, known as Wyrmspeakers, elect a dragonborn Emperor-General to lead their collective armies and defend their nation. Candidates for imperial rule, in turn, are traditionally selected from the most powerful warlords of the Five Shades.
This shifting web of interactions among the warriors and priests leads to the arbitrary rule of the Empire. One year, the Flametongues might lead the Imperial Legions to conquer new worlds, while the next, the Vinestalkers could instead plunder the treasury to build grandiose temples in the capital. Notably, the dragonkind have very little notion of hereditary rule. They are usually non-monogamous with weak family ties beyond a single generation. Legitimate rule comes from personal power, such as skill at arms or sorcery, and the respect and assent of their peers. On a larger scale, competition among the Shades drives the expansion of the Empire, as each faction seeks to increase its own glory, territory, and wealth in war and trade.
This pattern was broken in the Xoriat Wars, when the Mind Lords invaded the astral holdings of the Empire. The existential threat they posed led the Shades to band together to destroy the intruders. It also chipped away somewhat at the Empire’s strict racial hierarchy, with the Dragonborn forced to rely on their subject races to wage war. So long as the Mind Lords remain a threat, the factions continue to cooperate while their subjects become ever more integrated into the workings of the Empire.