How To Form Great Britain in EU4

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Forming Great Britain is available to countries whose primary culture is Highlander or is in the British culture group.

At the 1444 start, there are only three nations that meet that criteria:

  • England
  • Scotland
  • The Isles (Scottish vassal)

Of them, England and Scotland are recommended. They have a special method of forming Great Britain.



There are two decisions for forming Great Britain.

They both have these requisites in common:

  • At least Admin Tech level 10
  • Not a subject nation
  • Not at war

Note: You usually get Admin Tech 10 at around 1531.


Method 1: Form British Nation

This basic decision has these conditions:

  • London is part of a state
  • Own these core provinces:
    • London
    • Oxford
    • Hampshire
    • Lothian
    • Aberdeen

Method 2: Form British Nation Diplomatically

This variant is exclusive to England and Scotland. These are its conditions:

  • Has 100 Legitimacy
  • If you’re playing as England:
    • Scotland must be a vassal or a junior partner
    • Scotland must have less than 15 provinces
  • If you’re playing as Scotland:
    • England must be a vassal or a junior partner
    • England must have less than 41 provinces

The subject’s loyalty doesn’t matter. You’ll automatically annex/inherit them when completing this decision.

These’re In Your Decisions and Policies Tab / EU4
These Are In Your Decisions and Policies Tab

Strategies as England


1. Complete the “Levy the Troops” mission

This mission needs you to:

  • Reach 100% land force limit
  • Have at least 60% manpower reserves
  • Have at least 1 general

You already have a general at the start. You can complete the other two conditions within the first week of the game by doing these:

  1. Recruit mercenaries to reach your max land force limit
  2. Exploit the base manpower of your provinces

You’ll get these rewards:

  • “Subjugation” CB over Scotland
  • Permanent claims on the Scotland and the Ireland regions

The CB expires in 25 years though. You may want to hold off on claiming these rewards until you’re ready to declare war on Scotland.

English Claims Britannia / EU4
English Claims Britannia

2. Subjugate Scotland

It’s recommended to defeat France first before you attempt to vassalize Scotland. They’re guaranteeing Scotland’s independence at the start.

When you sue France for peace, demand that they annul treaties with Scotland to remove their guarantee.

Once Scotland’s on their own, you can then declare a subjugation war on them. You can easily siege down their capital and occupy their provinces. They’ll bend the knee eventually.

Vassalizing Scotland Using the “Subjugation” CB Still Requires 90% War Score / EU4
Vassalizing Scotland Using the “Subjugation” CB Still Requires 90% War Score

Strategies as Scotland

Unfortunately, your missions don’t give you a “Subjugation” CB over England.

You’re rewarded with permanent claims on them instead.

Secondly, England’s size makes it costly to vassalize them as an unjustified demand. You’ll need to annex some of their provinces first before that becomes possible.

Peace Deals Have a 100% War Score Max; England Needs 354% to Be Vassalized or Annexed / EU4
Peace Deals Have a 100% War Score Max; England Needs 354% to Be Vassalized or Annexed

That said, vassalizing them to form Great Britain diplomatically is still more efficient than the basic method.

You’ll save up on admin mana and you won’t get any aggressive expansion.

For a more in-depth guide on playing as Scotland, refer to this guide.

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Louie Nelson Zafico

As a frustrated otter who dreams of getting published, Louie instead wastes his life cuddling his cats. He spent his childhood playing Suikoden, grew up with Total War, and matured (somewhat) with EU4. He hopes to someday find a geopolitical JRPG with the 4X systems of a Paradox game.