EU4: How To Expand Inside the HRE

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The most annoying part of the HRE mechanics is certainly the increased aggressive expansion (AE) you accrue by conquering provinces. This makes expansion more difficult, because you will need to tone down conquest and be far more patient than usual.

“Aggressive Expansion Impact” and “Improve Relations” are a couple modifiers that find increased value in campaigns where you’re expanding from inside the HRE. That said, Espionage ideas can be a good first idea group if you cannot handle AE successfully.

 

Expansion Problems in the HRE

The HRE is comprised of small nations of various sizes, most of them with three or less provinces.

This means that reaching the 4 members required for a coalition to form against you is trivial.

Most members are also part of the same culture group, giving you even more AE towards them when you conquer their fellow countrymen.

 
The Germanic culture group dominating the HRE. / Europa Universalis IV
The Germanic culture group dominating the HRE.
 

On top of that, all provinces that are part of the HRE inherently cost extra AE to take. This can lead to some insane AE gains even from a single province.

Always check the projected AE before sending each peace deal!

Taking a province that you do not have a core on will allow the emperor to demand unlawful territory from you. You can of course refuse, but you will suffer big penalties to relations with other HRE members.

This makes it impossible to avoid coalitions by maintaining high relations with neighbors.

Finally, the HRE is dotted with free cities, all of which enjoy the emperor’s protection should you ever attack them directly. They also give double the normal AE which stacks on top of the inherent increased AE of HRE provinces.

 

Handling the Problems & Expanding in HRE

As mentioned in the introduction, grabbing AE reducing modifiers is an option.

Make good use of any temporary reductions you get from your mission tree or events. Even grabbing espionage ideas is a legitimate option, despite the idea group being considered meme tier.

 
The Espionage idea group, a great source of “aggressive expansion impact” reduction. / Europa Universalis IV
The Espionage idea group, a great source of “aggressive expansion impact” reduction.
 

“Improve Relations” is the superior modifier in my opinion.

AE is essentially an opinion modifier; one that ticks down yearly like all such modifiers do. Increasing your “Improve Relations” will also increase the speed AE fades away. Wait a decade or so and your AE will be close to zero again.

 
The Diplomatic idea group, a good source of “improve relations”. / Europa Universalis IV
The Diplomatic idea group, a good source of “improve relations”.
 

Unlawful Territory

Unlawful territory can be annoying, but it is not the end of the world.

Even if you have to decline the emperor’s demand every time you conquer land you should not worry much about the temporary negative modifiers.

 
The Unlawful Territory demand from the emperor. Make sure you never accept it by mistake. / Europa Universalis IV
The Unlawful Territory demand from the emperor. Make sure you never accept it by mistake.
 

Your main concern should be the possibility of the emperor attacking you to force you to release provinces.

In all my years of playing the game, it has never happened, no matter how weak I was compared to the emperor.

However, it’s always a possibility.

You can avoid unlawful territory by ensuring the emperor likes you. High relations are usually enough, but you should always ally them if possible. The sooner the better, because his opinion of you will get worse and worse every time you decline unlawful territory demands.

 
Allying Austria early on in a Dithmarschen campaign. / Europa Universalis IV
Allying Austria early on in a Dithmarschen campaign.
 

Free Cities

The empire starts with 12 free cities.

  • New cities can be created if the starting ones stop being eligible or get annexed
  • Free cities cannot have more than one province
  • All starting free cities are in Germany
 
The empire’s 12 free cities, all of them in German lands. / Europa Universalis IV
The empire’s 12 free cities, all of them in German lands.
 

Attacking a free city head on is out of the question. The emperor and all his allies will come to the city’s aid. If you can win that war, you might as well attack the emperor directly.

Here are your best options when handling free cities:

1. Becoming emperor and revoking their status

As the emperor, you can spend 5 Imperial Authority to revoke a free city. If you happen to get elected and do not want to play a campaign as emperor, spend your IA to revoke free cities you want to target.

 
The Revoke Free City Status, located under the “emperor actions” in the diplomacy tab. / Europa Universalis IV
The Revoke Free City Status, located under the “emperor actions” in the diplomacy tab.
 

2. Attacking an ally of theirs and eating the extra AE for annexing a non-co-belligerent

Attack an ally of the desired free city and make sure they enter the war.

Do not make them a co-belligerent because the emperor will defend them.

Make sure your AE is close to zero and demand nothing more than the single free city province!

3. Forcing them to conquer a province, making them ineligible for free city status

This can be quite tricky.

If they have a militarist ruler, you can ally them and help them conquer some land. Otherwise, include them in a war of yours, get 100% warscore on them and force them to accept a province of yours in the subsequent peace deal.

4. Feeding the land to an ally of yours

Attack an ally of theirs, call the free city in, and give the land to an ally of yours. They must want it, and it is very likely they will not want it because of the AE.

Even if the emperor demands unlawful territory from them, the released nation will not be a free city!

 

Expansion as a Non-Member

Attacking any HRE country as an outsider will call the emperor into the war.

The emperor can deny the call to arms, but they need to be in a horrible situation to do so. You will need to employ cunning to expand into the HRE.

Here are your options:

  • Attack an Ally – The same trick you employ on free cities. Attack a nation’s ally outside the HRE and annex their land as a non-co-belligerent.
  • Join the HRE – If you have less than 200 development, you can manually join the HRE by having high enough relations with the emperor and your capital bordering the HRE. Some nations even get events from their mission trees that make them part of the empire.
 
The “Join HRE” button on the bottom left of the HRE UI. / Europa Universalis IV
The “Join HRE” button on the bottom left of the HRE UI.
 
  • Become Emperor – Being the emperor allows you to join the HRE. On top of that, being the emperor does not forbid fighting other HRE members. Even if you do not join the empire, you can conquer land far easier as there is no one to defend your targets!
  • Dismantle the Empire – Well, without an empire, there are no annoying mechanics to stop your conquering spree. You will need all electors and the emperor’s capitals under your control. Then you just press the relevant button on the bottom of the HRE UI and boom! No more HRE.
 
HRE UI. “Dismantle Empire” on the bottom will show the necessary capitals when you hover over it. / Europa Universalis IV
HRE UI. “Dismantle Empire” on the bottom will show the necessary capitals when you hover over it.
 

General Tips for Expansion in the HRE

1. Use Your Diplomats

Countries with positive relations will not join a coalition against you, while countries already in a coalition will leave it if they have more than 60 relations with you. Keep your diplomats constantly improving relations.

2. Ally the Emperor

This was mentioned before, but it is very important. It also synergizes with the strategy of keeping positive relations with other members.

An allied emperor will not demand unlawful territory, which in turn will not lower other members’ opinion of you.

3. Be Patient

There is no reason to be impulsive.

Win your wars, demand land that will NOT get you over 50 AE, and then take money, war reparations, trade transfer, humiliation, etc.

Money and extra monarch power can be worth more than a troublesome piece of land.

4. Use Vassals

Strategically vassalizing countries with cores on foreign land is a legitimate way to minimize AE.

You can attack a nation, take a single province, and give the rest to your allies. Release the nation and take its rightful land back from your allies either through favors or war.

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G. Tsechilidis

Born and raised Greek citizen. His love of history, geography, and all things map-related, are certainly a contrast to his pursuit of a master in civil engineering. An avid gamer from a very young age, he found the perfect match in Grand Strategy Games. If not for a good chess match or a round of carambole billiards, you'll certainly catch him firing up EU4 or a Total War game to spend the evening.