Summary at a glance
Goal: Use vassals and subjects to expand without control penalties and reduce aggressive expansion.
Do this first:
- Vassalize nations with cores for reconquest CB (-50% AE)
- Keep liberty desire below 50% at all times
- Wait 20-50 years before integrating (enjoy tribute income first)
Pitfall to avoid: Integrating too early wastes tribute income. Keep vassals longer to enjoy their benefits.
Vassals and subjects are powerful tools for expansion without control penalties. This guide covers how to effectively use subjects to build and maintain your empire.
Subject Types
- Vassals: Traditional feudal subordinates, provide military support and tribute
- Marches: Military-focused vassals with enhanced army bonuses
- Client States: Custom-created subjects, highly loyal
- Colonial Nations: Automatically formed in colonial regions
- Personal Unions: Dynastic unions (monarchy-specific)
- Tributaries: Pay tribute but maintain independence (East Asia focus)
Creating Vassals
Method 1: Diplomatic Vassalization
Requirements:
- Target must be much smaller than you (development < 50% of yours)
- High trust (60+)
- Positive relations (150+)
- Target not in defensive alliances
- Not a rival
Process: Diplomacy → Vassalize offer → Accept
Benefit: No aggressive expansion penalty
Drawback: Requires long diplomatic preparation
Method 2: War Vassalization
Process: Win war → Peace deal → Vassalize option
Cost: Moderate aggressive expansion (less than annexation)
Benefit: Fast, doesn't require diplomatic preparation
Strategy: Target small nations (1-3 provinces) for easy vassalization
Method 3: Releasing Vassals
Process: Diplomacy → Release subject → Select cores
Benefit: No aggressive expansion, immediate loyalty
Use Case: Reconstitute nations from conquered land to reduce control strain
Subject Income & Benefits
Tribute Income
Vassals provide monthly tribute based on their income:
- Vassal: 10% of their income
- March: 0% (military focus)
- Colonial Nation: 50% of trade income in their region
- Tributary: 25% of their income
Maximizing Tribute:
- Help vassals develop economically (subsidize, build in their land)
- Protect their trade routes
- Grant them strategic conquests to increase their income
Military Support
- Vassals: Provide armies in your wars (max 100% of their force limit)
- Marches: Provide enhanced armies (+30% morale, +20% discipline)
- Colonial Nations: Provide naval support and colonial troops
Integration
Integration Process
Integration converts a subject into your core territory.
Requirements:
- Vassal relationship for 10+ years
- High trust (80+)
- High loyalty (80+)
- Not at war
Cost:
- Gold: 50-500 depending on subject size
- Stability: 50-150
- Diplomatic power equivalent
Time: 5-15 years depending on:
- Subject development
- Administrative efficiency
- Integration speed modifiers
Strategy: Integrate small subjects first, leave large subjects as vassals longer
Integration Speed Modifiers
Positive
- Administrative efficiency (+20% to +50%)
- Same culture group (+25%)
- Government reforms (+10% to +30%)
- High trust (+15%)
Negative
- Large subject size (-30% to -50%)
- Different culture (-20%)
- Different religion (-15%)
- Low loyalty (-10% to -30%)
Subject Liberty Desire
Liberty Desire Factors
Increases Liberty Desire
- Relative military strength (subject stronger than overlord)
- Influenced by rivals (+20 to +50)
- Negative relations (-10 per -10 relations)
- Different culture/religion (+5 to +15)
- Harsh treatment (-10 to -30)
Decreases Liberty Desire
- High trust (-50 at 100 trust)
- Military superiority (+strong overlord)
- Subsidies (-5 per subsidy)
- Supportive stance (-10)
- Recent grants of land (-10 to -20)
Managing Liberty Desire
Strategies:
- Improve Trust: Send gifts, fight alongside them, guarantee their independence
- Maintain Military Strength: Keep larger army than subject
- Grant Privileges: Reduce tariffs, give trade benefits
- Develop Their Land: Build buildings in subject territory
- Placate: Use diplomatic actions to temporarily reduce liberty desire
Strategic Vassalization
Reconquest Strategy
Concept: Vassalize a nation with many cores, then declare reconquest wars
Benefits:
- Reconquest has -50% aggressive expansion
- Vassal gains cores instantly (no integration time)
- Efficient large-scale conquest
Example: Vassalize Byzantium → Reconquer Greece/Anatolia → Reduced AE
Best Targets: Nations with large historical cores (Byzantium, Persia, Delhi)
Buffer Vassal Strategy
Concept: Create/maintain vassals on borders to absorb enemy attacks
Benefits:
- Vassals absorb first wave of enemy attacks
- Defensive wars easier to win
- Reduced direct border with rivals
Example: Keep small vassals on Ottoman border while you expand elsewhere
Administrative Vassal Strategy
Concept: Use vassals to administer distant/low-control territories
Benefits:
- No control penalties (vassals have their own control system)
- Vassals develop the land independently
- You receive tribute without administrative burden
Example: Create colonial subjects to manage overseas territories
Marches: Military Vassals
Creating Marches
Process: Diplomacy → Grant March Status (to existing vassal)
Requirements:
- Existing vassal
- Border with rival or enemy
- Not a colonial nation
Effects:
- Vassal loses tribute obligation
- Gains +30% morale, +20% discipline, +20% fort defense
- Reduced liberty desire (-30%)
When to Use Marches
Best For
- Border defense against strong rivals
- Military-focused vassals with strong ideas
- Regions you don't plan to integrate
Don't Use For
- Small, weak vassals (wasted bonuses)
- Rich trade vassals (you lose tribute income)
- Subjects you plan to integrate soon
Colonial Nations
Formation
Colonial nations form automatically when you have 5+ provinces in a colonial region.
Colonial Regions: Americas, Australia, parts of Africa
Process: Automatic at 5 provinces → Forms new subject nation
Effects:
- Former provinces become subject's territory
- Subject administers region independently
- You receive 50% of trade income routed through their trade nodes
Managing Colonial Nations
Tariffs: Set tariff level (0-50%)
- High tariffs: More income, higher liberty desire
- Low tariffs: Less income, lower liberty desire
Military Support: Colonial nations provide armies/navies for your wars
Development: Colonial nations build and develop independently
Common Mistakes
- Integrating Too Early: Integration is expensive and slow. Keep vassals longer to enjoy tributary income and military support.
- Ignoring Liberty Desire: Subjects above 50% liberty desire will seek independence. Monitor and manage proactively.
- Not Using Reconquest CB: Reconquest is extremely powerful for reducing aggressive expansion. Vassalize nations with cores before conquering their lands.
- Creating Too Many Small Vassals: Administrative burden. Better to have 2-3 large useful vassals than 10 tiny ones.
- Wrong March Placement: Don't grant march status to wealthy trade vassals. Use it for military-focused border vassals only.
- Forgetting to Build in Subject Land: You can build in subjects' territories. Use this to boost their income and your tribute.
Quick Reference
- Optimal Vassal Size: 3-8 provinces (manageable, useful, not threatening)
- Integration Timing: 20-50 years after vassalization (wait for high trust/loyalty)
- March Conversion: Only for border military vassals
- Colonial Tariffs: 20-30% (balance income and loyalty)
- Liberty Desire Threshold: Keep below 50% at all times
- Trust Target: 80+ before integration
- Reconquest AE Reduction: -50% (extremely valuable)