Shards of Sehanine
The Arkhosian Empire
Arkhosia was an ancient empire of Dragonborn, ruled by Dragons.
Although most people nowadays believe Arkhosia was a single empire, in truth it was more akin to a federation of city states. Each of these city states was ruled by a dragon. The Arkhosian Empire itself was ruled over by the Dragon Emperor, most often a metallic dragon of enormous stature and might.
Ironically the war with Bael Turath initially served to strengthen Arkhosia as the city states unified against their common enemy.
Concerning theology, Bahamut was considered the patron God of Arkhosia as the benevolent half of Io. Naturally, secretive cults of Tiamat sprang up like clockwork throughout the empire, causing internal friction and strife.
Arkhosia had a strict hierarchy. At the very top the Dragon Emperor stood alone. In theory at least the Dragon Emperor had absolute authority in Arkhosia, though it took until the war with Bael Turath before this became truth. The Dragon Emperor was usually a metallic dragon throughout the long history of Arkhosia, although there have been chromatic Emperors as well.
Below the Dragon Emperor were the Regal Lords. These were the Draconic rulers of the citystates of Arkhosia, each of them a powerful lord in his or her own right with armies of Dragonborn to command.
Advising the Emperor and the Regal Lords were councils of lesser Dragons. Each Dragon was nobility in the Arkhosian Empire, with the Dragonborn as their subjects. Each citystate had their own style of council, though most citystates tended to congregate around one type of dragon. For example, the citystate of Dagoith was usually ruled by brass dragons, ensuring that the council would engage in dialogues over even the most minute of details that could last for days at a time.