The real Byzantine Empire lasted for over a millennium and stretched across the Mediterranean nations as a powerful autocracy, but that's only because it didn't spend a devilishly long time figuring out Crusader Kings 2's multiplicative complexity. Of course, Paradox's excellent dynasty simulator luckily exists today, and it's getting a visit from Constantinople itself in the Legacy of Rome expansion releasing later this year for $10.
Besides bestowing greater control on levies, taxes, and opening up a bigger slice of the world to manage, Legacy of Rome introduces royal factions for disgruntled and proponent vassals to participate in either uplifting your cause or clamoring for your head. Factional revolts can also break out if too many vassal feathers get ruffled, and just for another chance to say "vassal" (because it's a funny word), vassals also aid in appointing new standing armies within your realm.
Here's a brief rundown of the expansion's features:
- New Faction System: Join a royal faction and use your allies in the party to enhance your strength and tear down rivals
- Raise Standing Armies: You will now be able to use retinues to have standing armies in your domain: the size of which is determined by technology
- Experience Factional Revolts: No more easily defeated rebellions. Disgruntled vassals will now band together in revolt against your rule through their faction
- Appoint Orthodox Patriarchs: Orthodox kingdoms and empires can now control their own heads of religion and their powers, instead of being dependent on the patriarch of Constantinople
- Streamlined Mobilization: You will always raise a single, larger levy from your direct vassal; no need to worry about the opinions of the lower vassals
- Leader Focus on Combat: Appoint your generals wisely, their traits and skills are now of vital importance on the field of battle. More commander traits are now added to increase the importance of your choice of military leaders
- Byzantium Comes Alive: New sets of decisions and events specifically designed with the Byzantine Empire in mind
- Improve your ruler: You can now actively strive to improve your skills or traits through the new Self-Improvement Ambitions