The Known Worlds is rife with factions. Some have risen and others have crumbled over the centuries since the Fall, but many have proved quite durable.
Society cannot share a common communication system so long as it is split into warring factions.
— Bertolt Brecht, “A Short Organum for the Theatre”
These factions, the major Royal Houses, Church sects, and Merchant League guilds, pretty much rule the Known Worlds. Of course, the Emperor is the nominal ruler, but he cannot dramatically change the status quo without riling the existing estates. Emperor Alexius has spent years slowly cementing his power, knowing that upon his death, his family’s hold could crumble if he doesn’t appease those who will choose his successor. When Alexius must anger one, he must first placate two others to back him.