This is my guide how to manage large empires.
If you want to play tall and live happily with your small nation throughout game time this guide is not for you.
So you decided to try Imperator: Rome and chose a nation to play hoping that you can historically conquer whole Roman Provinces as Rome or Reclaim Alexander's Empire as any Greek nation or build an unhistorical custom empire.
So you have two options logically; play a small nation like Rome, Sparta etc. then expand or choose a faction that has already been an Empire at the start like Seleucids, Egypt, Macedonia etc.
My guide addresses both options as the problems they will face are exactly same.
No matter what size of your initial nation size your first problems are:
- Not enough manpower.
- Aggressive expansion penalty.
- Lack of money.
Your first aim is to have a large army that is enough to conquer enough lands to feed at least 100k standing army. For example, as Rome you need whole Italian Peninsula, any small Greek nation needs at least 3 Regions.
In my tests and observations in early game you should rule at least 3 Regions (not provinces). As you are low at tech to sustain our first target, 100k standing army you will need more lands at least 3 totally conquered regions.
For existing Empires will face a dilemma to spend your resources to pacify your unruly land by building temples and theatres to convert them to your state religion and culture or spam the might of your empire immediately. If you choose the first you need at least 20 to 50 years of peaceful era. If you choose the second you will face same problem like any expansionist nation: aggressive expansion penalty.
Your first war must be against a faction that has same or close culture (in the same culture group).
The most obvious ones are Italy Region (not who peninsula, click the region tab to see it.) for Romans, Syria for Seleucids, any Greek neighbours for small city states etc.
After First War
So you conquered a neighbour and tasted first blood of your enemies.
The game gives you many options for elite families; kill them all, banish etc. I personally choose banishments to get small aggressive expansion reduction for Roman players who wants to go Empire may imprison each family then choose their fate one by one to get popular support to invoke the decision to form dictatorship.
You have taken a huge hit on your manpower pool if you are small nation or a huge aggressive expansion if you are an empire.
Before beginning to express how to solve money, manpower and AE (aggressive expansion) problems in their sections, you should observe your neighbours ' allies, clients, pact members etc. in the next section.
Divide et Impera (Divide and Conquer)
Any nation may form different types of bonds with any other state. It may be a defensive pact, a formal alliance, foederati, client state, satraps for Iranians etc.
Subject nations like Latin allies of Rome, any satraps, enters the wars with overlord. Vassal tribes, tributaries do not. So you will count whole manpower pool of the target nation and its subjects.
If your target state has no subjects you may see them forming alliances or defensive pacts. If your target is a tributary only its overlord will help it.
So basically after you get a claim you will see who will participate the war against you. Thanks to rich trade bonuses and other things consuming enemy manpower is not enough to make them kneel you have to hit them hard economically to prevent them hiring mercenaries.
After playing chess and maybe reading Sun Tzu's Art of War you will stick the first rule "Know your enemy!".
Your strategy is as title says dividing alliances, conquering them one by one. You will have many reports that even the best generals lacks the ledger. Use it.
In diplomacy screen you will see any relations. In trade screen click block capital bonuses trade offers you will need capital bonus for yourself.
100k Standing Field Army
So after this section I assume you have at least 3 whole Regions, 100k standing field army, enough money to sustain them and of course 100 ships to carry them if you are not landlocked.
Here I intentionally separate my land army into two. Regional Troops and Standing Operation Army.
You need to assign some troops to quell unrest -4 unfortunately hardcoded. You can name them like Milites of Transalpine Gaul or any other way.
If you do not know how to, you need any army with no general then click the army orders tab then click assign the region order.
With operational army you focus your army into strategical locations like mountain passes, province capitals, river crossings etc. You need to divide your army into 3 duties siege and harassment and holding strategical locations. Your regional army cannot cross any other region. Remember that. I use them to hold strategical locations and operation army to siege and harassment.
As your defence is offence to harass your enemy you need navy or fast troops full cavalry to escape from enemy pursuit.
Thanks to mercenaries. You need to land troops to occupy unguarded territories mostly not in the zone of control of forts. Check or click fort sign to see its map. If you occupy a territory you enslave some pops and kill some other then return to ships or friendly zone if you are landlocked.
Historically Romans finally vanquished Carthage after 3rd Punic war. In my Roman campaign I just finished 2nd and looks like I need 3 more to wipe them out.
As a side note: Carthage landed 25k units on Italy yes it did but in the middle of 45k regional units. Do not forget to UNassign them from governors if you face homeland invasions. Or you may try expensive option : Build the coastal Mediterranean Wall namely build forts to control coastal territories. Or wipe out enemy navy first. After 100 years I do both :)
Finally Internal Affairs
After this section I will express my strategies how to manage internal crises, revolts, civil wars, pop managements, slave revolts etc.
After some conquest to finance a huge army and spare at least 50+ gold monthly for building your empire we can finally focus on our own population in fact pops in short in game.
Our main goal is to keep them happy, efficient and equal (cough cough, not unfortunately in rights but in numbers.) Other than tribal nations you must enforce policies to have 33% of citizens, freemen, slaves that is the utmost goal.