The first estate of power is that of the nobility and contains both the Imperium and the Noble Houses. Of the many noble houses throughout the Known Worlds, five have achieved prominence and effectively ruled most of Human Space - under their new Emperor, of course. The Emperor Wars took a toll on many of these houses: the losers now struggle to regain lost lands or power, while the victorious fight to ensure that their rivals stay down.
The Universal Church of the Celestial Sun The Church's decrees affects the lives of countless billions of citizens of the Empire. The Church is not wholly united as it often is split into sects and orders. There are five major sects of the church as well as many mendicant or Heyschast orders as well as certain other sects and orders.
The Merchant League is the remnant of the Second Republic, a union of Mercantile Guilds who ensure that the economy of the Empire is maintained. Five major Guilds have risen to power and are surrounded by numerous Minor Guilds.
Ruling the disparate masses of the Known Worlds many other factions also vie for power: