Archdukes of Hell

From his throne at the bottom of the Nine Hells, Asmodeus commands a sprawling bureaucracy tied to a massive war apparatus dedicated to turning back the demons that invade the uppermost realm of Avernus, and to taking the fight to the other planes, including the Abyss, whenever the opportunity arises.
Asmodeus and the other archdevils rule over the nine layers that comprise the Hells. The devil lords make up a hierarchy that is both rigid and fragile. Although Asmodeus is more powerful than any other lord, he has to be constantly wary of treachery within his ranks. It could be said that the true ruler of the Nine Hells is the immense body of rules and regulations that dictate how all devils, even Asmodeus, must conduct themselves.

Layer Name and Ruler

1. Avernus -- Zariel, Archduchess of Avernus 
2. Dis, Iron City of -- Dispater
3. Minauros -- Mammon
4. Phlegethos -- Belial and Fierna
5. Stygia -- Levistus
6. Malbolge -- Glasya
7. Maladomini -- Baalzebul
8. Cania -- Mephistopheles
9. Nessus -- Asmodeus