Sons of Ironhold
The Sea of Nations
Between the great powers lies a vast swath of inland territory where they fight their proxy wars. The names and borders of these areas shift constantly. Many of these nations have kings, queens, or leaders with other titles. These client rulers may occasionally play one side off against another to gain some autonomy for a time, but in general they must swear fealty to one empire or another.
They usually have a wide authority to make local laws, observe local customs, and of course enrich themselves so long as they (1) keep the ranks of their armies filled with recruits and draftees, (2) send those armies against their sponsor’s enemies when and where they are asked, (3) provide a good military showing in such battles, and (4) provide tribute when asked.
Cheat Sheet: Influenced by the Pre-Unification German states.