Crusader Kings 3: How to Form the Roman Empire (2024)

Some of the most fun you can have in Crusader Kings 3 is achieving an ahistorical success. Instead of letting the Byzantine Empire rot and fall, you can help it reclaim the entire Mediterranean. Instead of watching the Karling dynasty fall to ruin, you can reforge the Holy Roman Empire and reunite all of Western Europe.

In both those specific cases, you can also reclaim the legacy of Rome by enacting the "Restore the Roman Empire" decision. This decision is one of the most powerful in all of Crusader Kings 3, and it comes with some long-lasting benefits, but you'll need to meet some tricky requirements to achieve it.

The Requirements for Restoring the Roman Empire

The first requirement for the "Restore the Roman Empire" decision is that you must control the Byzantine Empire title, the Holy Roman Empire title, or both. The Roman Empire decision won't show up in your Decisions menu unless you own at least one.

However, these empires don't have to be your primary title. This means you can invade the Mediterranean from the outside, create one of the titles by controlling enough of its territory, and then Restore the Roman Empire on the same day (assuming you meet the decision's other requirements). Keep in mind that the Holy Roman Empire doesn't exist during the 867 starting date, and it doesn't always form on its own, so you may need to focus on the Byzantine Empire if this is your approach.

Once the decision appears in your menu, you must meet the listed requirements:

• Your character's Level of Fame (Prestige) is 5.
• Your empire completely controls every county in the following duchies:
  • Latium (Rome)
  • Venice
  • Romagna (Northeast Italy)
  • Sicily (the island)
  • Genoa
  • Capua (south of Rome)
  • Apulia (the heel of the Italian boot)
  • Thrace (Constantinople)
  • Antioch (the Mediterranean coast northeast of Cyprus)
  • Palestine (Jerusalem)
  • Alexandria (western Egypt)
  • Athens (in Greece)
  • Tunis (southwest of Sicily)
  • Croatia (northeast of Italy)
  • Thessalonika (the three-pronged peninsula north of Greece)

Aside from that, you don't need to pay any Gold, Piety, or Prestige to enact this decision. However, there are a few extra requirements that Crusader Kings 3 doesn't tell you about. If you don't meet them, "Restore the Roman Empire" will stay gray no matter how much of the Mediterranean you own.

• Your government must be Feudal or Clan, not Tribal.
• Your character must be an adult, and not in prison.
• If you hold the Byzantine Empire, your character must meet one of these requirements:
  • Christian (any Faith works)
  • Greco-Roman (reformed or unreformed)
  • Roman culture
• If you hold the Holy Roman Empire, your character must meet one of these requirements:
  • A Latin-heritage culture and any Christian Faith
  • A Latin-heritage culture and any Greco-Roman Faith
  • Roman culture

Note that the Roman culture and the Greco-Roman faith don't normally appear in the game during the earlier or later starting dates. Unless you create a ruler with these conditions, your best bet for restoring the Roman Empire is to start as a Christian or convert to Christianity (at least temporarily).

Tips for Restoring the Roman Empire

• It's easier to restore the Roman Empire as the Byzantines than as the Holy Romans, because the Byzantines start out with many of the needed duchies and de-jure claims on three of the others. They're also closer to the Islamic empires of the Middle East (for better and worse).
• The easiest way to get much of the needed land as the Holy Roman Emperor (or a Karling king who quickly forms the Holy Roman Empire) is to marry into the Byzantine Empire's ruling family. This should give your heir the claims they need to conquer and combine the two empires.
• You can also find a claimant to the Byzantine throne, marry them to your current ruler, and then fight a war to put them on the throne. With luck, your primary heir will inherit both titles, and if they don't, they'll get a strong claim to both.
• Christian heresies (any Christian faith without Ecumenism) can freely declare holy wars against other Christian rulers. If your empire is stable and safe, converting to or creating a heresy may make it easier to conquer the north Mediterranean duchies without disqualifying you for the "Restore the Roman Empire" decision.
• The duchies needed to restore the Roman Empire overlap with the duchies needed for the "Mend the Great Schism" decision. Doing this will remove Ecumenism from all other Christian Faiths, making them fair game for holy wars, but much of the Christian world will convert to your Faith at the same time. This makes peaceful relations easier, but conquest harder.
• You don't need to dismantle the Greek or German pretenders to restore the Roman Empire.

The Benefits of Restoring the Roman Empire

Once you enact the "Restore the Roman Empire" decision, you get several immediate benefits:

• Your ruler gets a new nickname, "the Glorious."
• Your ruler gets the trait Augustus, which gives them 0.5 Prestige per month and +10 opinion with all Vassals. This trait passes to whomever rules the Roman Empire.
• The game destroys every Empire title your ruler holds and replaces it with the Roman Empire. If you hold several titles, you'll become the de jure liege of a much larger region overnight. That means no having to wait for de jure drift and no risking your empire falling apart in a partition.
• If you controlled the Byzantine Empire, your map color becomes red, and you get a red-and-gold coat of arms. If you controlled the Holy Roman Empire, your map color stays white, and you get a red, white, and gold coat of arms. If you prefer different colors, remember that you can customize any controlled title's name, map color, and coat of arms by selecting the pen-and-ink icon next to the title's name.

You also get several lingering benefits you can take advantage of as you continue to rule the Roman Empire:

• You can at any point choose the "Reclaim Rome" decision and make the county of Roma your capital. This decision still works if you moved your capital recently, and it causes no relationship loss with whomever owned Roma before. However, it doesn't give you the duchy of Latium or the other two counties in the duchy.
• You gain access to the special "Restore Imperial Province" casus belli. This lets you start a war for a duchy with any other ruler, regardless of your claims or their religion. What's even better is that this CB is free. Just keep in mind that this casus belli counts as a "conquest" war, which means any dukes or counts in the duchy will keep their jobs when you take over. The "Restore Imperial Province" CB works for the following regions:
  • All of Hispania
  • All of Francia
  • All of Italia
  • All of the Byzantine Empire
  • England
  • Maghreb
  • Tahert
  • Africa
  • Egypt
  • Jerusalem
  • Syria
  • The duchies of Istria and Krain
• Each time you completely restore a kingdom or other large region to Roman rule, the game will spawn an event to congratulate you and give you 350 Prestige. These congratulations also appear when you conquer certain regions outside the "Restore Imperial Province" range, including Ireland, Germany, and Mesopotamia. However, these extra events stop appearing if your ruler no longer meets the personal requirements for "Restore the Roman Empire."

If only for the merged Empire titles and the free casus belli, plenty of rulers have a good reason to restore the Roman Empire, even if they don't normally rule a Christian empire. It may take a little extra effort, but even an Islamic or pagan emperor can benefit from claiming the legacy of Rome.

Crusader Kings 3

Platform(s)

PS5 , Xbox Series X , Xbox Series S , PC

Developer(s)

Paradox Interactive

Genre(s)

RPG , Grand Strategy

Multiplayer

Online Multiplayer

ESRB

T for Teens: Drug Reference, Language, Mild Violence, Suggestive Themes