Byzantium EU5 Guide
Restore the Roman Empire using the Vassal Release exploit strategy. Avoid both disasters, crush the Ottomans in under 10 years, and build a powerful economy from vassal tributes.
Patch 1.0.9 Exploit Warning
Why Byzantium?
Byzantium is the legendary challenge nation of EU5—the underdog story everyone wants to play. The dying Eastern Roman Empire, surrounded by enemies, crippled by disasters, with an economy that produces almost nothing. Most players struggle for dozens of hours just to survive the first 20 years.
This guide changes everything. Using the Vassal Release strategy, you'll eliminate both major disasters, generate positive income from day one, and fully annex the Ottoman Empire within 9 years. It's essentially cheating—but it works perfectly in patch 1.0.9.
Byzantium's Starting Problems
Problem #1: No Economy
Every estate has "corruption privileges" that reduce maximum tax by 25% each. Combined with other negative modifiers, you earn almost nothing from your land. The Nobility privilege also reduces army morale by -20%.
Problem #2: Byzantine Succession Crisis
This disaster reduces crown power by -20%, state satisfaction equilibrium by -25%, and increases pretender growth. The key detail: it requires Byzantium to have more than 2 provinces to trigger.
Problem #3: Coup Disaster
A secondary disaster that triggers with low legitimacy. Unlike the Succession Crisis, this one is manageable—it lasts only 5 years and actually gives events that provide stability and legitimacy.
The Vassal Release Strategy
The core innovation: since you don't make money from your land anyway (corruption privileges), just give it all away. Release everything as vassals and fictims, reduce Byzantium to 2 provinces, and become ineligible for the Succession Crisis forever.
Opening Moves Checklist
- 1Release all provinces as vassals except Constantinople + 1 cross-strait province (keep the one across the Bosphorus for high harbor capacity access)
- 2Create equal mix of Fictims and Vassals to manage liberty desire and diplomatic capacity
- 3Max diplomatic spending immediately to keep vassals loyal
- 4Max court spending to rush legitimacy to 30% (avoids Coup), then 100% (enables privilege revocation)
- 5Leave cabinet empty initially—don't increase estate power further
- 6Push decentralization—you have no land, so centralization bonuses are worthless right now
- 7Start spy network in Ottomans immediately—you'll need claims for war
- 8Rival Morocco, Yemen, Tunis, or Mamluks—nations you won't interact with
Economy Without Land
After releasing your provinces, something magical happens: your court costs collapse. With a tiny 2-province nation, you're suddenly making a profit of ~4 ducats per month—unheard of for traditional Byzantium.
Income Sources
- • Vassal tributes — Your primary income stream
- • Minting gold — Carefully manage inflation (starts at ~9.5%)
- • "Lenders in Chaos" event — Removes loans for free
- • Reduced court costs — Tiny nation = tiny expenses
Economic Tips
- • Vassals improve their land → pay you more tribute over time
- • Drop diplomatic spending to ~50-66% once vassals stabilize
- • Don't pay off debt—wait for the event that removes it free
- • At 100 legitimacy, you'll earn ~10 ducats/month
Disaster Avoidance
Succession Crisis: AVOIDED
With ≤2 provinces, you're permanently ineligible. The disaster cannot trigger as long as you maintain your tiny nation size during the early game.
Coup Disaster: AVOIDED
Reach 30% legitimacy by maxing court spending. This usually happens within the first few years. Even if it triggers, it only lasts 5 years and gives good events.
Vassal Management
Managing your vassal swarm is critical. You'll be over your relationship limit—that's fine. The loyalty penalty and crown power loss don't matter when you have no land producing income anyway.
Vassal Loyalty Tools
- Diplomatic spending slider — Keep at 50-66% once stable, push to max if anyone becomes disloyal
- Invite to Ecumenical Church — Gives +10 opinion (50-year cooldown)
- Support Loyalists — Emergency button for +20 loyalty instantly
- Parliament: "Increase Ties to Subjects" — Gives -5 liberty desire per vassal and +10% subject income while active
Crushing the Ottomans
Once your spy network in the Ottomans hits 20, fabricate a claim on Bursa (their most valuable province). Even if the Ottomans have expanded significantly, your vassal swarm will overwhelm them.
War Strategy
- 1Naval superiority — Your starting navy massively outnumbers the Ottomans. Blockade the straits immediately.
- 2Call up all levies — Combine your forces with your vassals. You'll outnumber the Ottomans significantly.
- 3Engage directly — Even with the -20% morale penalty from privileges, you have overwhelming numbers.
- 4Full annex the Ottomans — Remove them from the game entirely. Peace out their allies with minimal land.
- 5Create more vassals from conquered land — Hand out Ottoman territory to new vassals, keeping only coastal cores for yourself.
Post-War: Vassal Reintegration
After defeating the Ottomans, it's time to reintegrate your vassals. The key mechanic is "Return Land"—since you still have cores on the provinces you released, you can demand them back while annexation is in progress.
Reintegration Strategy
- Start annexation of a vassal (note the total cost, e.g., 106 for 8 rural + 1 town)
- Use "Return Land" to demand provinces back—each one reduces annexation cost by 20
- Manage liberty desire with Support Loyalists (+20 loyalty) to offset the Return Land penalty (+20 liberty desire)
- Repeat until the annexation cost is minimal, then complete the annexation quickly
Privilege Revocation Priority
Once you hit 100 legitimacy, you can start revoking the corruption privileges. Prioritize based on estate power (lower = cheaper to revoke) and impact.
Peasant Corruption Privilege
Lowest estate power = cheapest to revoke. Peasants pay majority of your tax.
Nobility Corruption Privilege
The -20% army morale is brutal. High priority despite higher revocation cost.
Burger & Clergy Privileges
Lower priority. Revoke when you have stability to spare.
Research & Advances Priority
Rush down the diplomatic side of the tech tree for vassal management:
- Subject Loyalty — Helps keep your vassal swarm under control
- Subject Opinion — Further loyalty bonuses
- Diplomatic Annexation — Faster vassal integration
Also grab: Organized Religion, Guilds, Peasant Connections for general bonuses.
Common Mistakes to Avoid
Keeping more than 2 provinces
This triggers the Succession Crisis. Release everything except Constantinople + 1.
Investing in stability before legitimacy
Legitimacy is faster and cheaper to raise. Max court spending for legitimacy first.
Paying off loans manually
Wait for the 'Lenders in Chaos' event that removes loans for free.
Appointing cabinet members early
This increases estate power. Leave cabinet empty until you've stabilized.
Pushing centralization immediately
You have no land! Decentralization helps with vassals. Centralize later.
Accepting unfavorable events
Turk tribe demanding 100 gold? Say no. They can't do anything about it.
Not building spy network immediately
Start on Ottomans from day 1. You need claims for the war.
Setting vassals to Scutage before Ottoman war
You need their armies to overwhelm the Ottomans.
Campaign Timeline (1337-1350)
Day 1: The Setup
- • Release all provinces except Constantinople + cross-strait province
- • Max diplomatic + court spending
- • Start spy network in Ottomans
- • Set up decentralization push
Years 1-3: Stabilization
- • Reach 30% legitimacy → Coup disaster avoided
- • Economy turns positive (~4 ducats/month)
- • Manage vassal loyalty with diplomatic spending
- • Continue spy network, fabricate claim on Bursa
Years 4-9: Ottoman War
- • Declare war once spy network is ready
- • Naval blockade + vassal swarm overwhelms Ottomans
- • Full annex Ottomans, peace out allies
- • Create new vassals from conquered territory
Years 10+: Consolidation
- • Reach 100 legitimacy, start revoking privileges
- • Begin vassal reintegration with "Return Land" mechanic
- • Economy grows to ~10 ducats/month
- • Decide whether to trigger or permanently avoid Succession Crisis
Why This Guide is Accurate
This guide is based on tested gameplay in EU5 patch 1.0.9. The Vassal Release strategy has been verified to work as described—both disasters avoided, Ottomans fully annexed within 9 years, positive economy from day one. However, this exploit will almost certainly be patched in a future update. Use it while you can!
