Select the army
Open the army panel
Click the split army button
Choose how many regiments to move
Confirm the split
Move the new army to the desired location
Open the diplomacy interface with the target country
Select the diplomatic action you want to send
Check that you meet the required conditions
Confirm the action to...
Open the Diplomacy or Subjects interface
Check the Subjects tab to view your vassals
Hover over your country’s subject icon in the top bar
Open the Ledger...
Open the Union interface
Select the relevant Union
Check the current Integration Level requirement
Increase Union Cohesion through member participation
Complete Union tasks and objectives
Contribute resources or influence...
Keep unrest low with autonomy, stability, legitimacy, and accepted cultures
Station troops in high-risk provinces before revolt progress completes
Use harsh treatment if you need immediate...
