Roman Mid-Republican Army Composition for Divide et Impera (DEI)

A guide to creating a historically accurate Mid-Republican Roman Army.

A Brief Introduction

The Total War series has been one of my favorite video game franchises for almost 8 years. As a history enthusiast, my preferred style of play is creating accurate representations of how armies fought in the ancient world.

While I understand there are other guides on Steam and various Total War forums, I personally never found one I was satisfied with. I often found myself using them as a loose guideline for the type of army I wanted to make. Hopefully, this guide will help serve as a basis for anyone wanting to recreate a Roman legion during the Mid-Republican period.

The change in unit sizes and variety of troops in DEI allows you to create a consular army with a nearly perfect 6:1 ratio. Personally, I like to play with two combined armies totaling 40 units to get an even closer 3:1 ratio.

Please be aware at the time of this guide, the current version of DEI is 1.04a. On ultra settings, this version has 200 men in each Roman unit. In the past, this mod used to have 240 men.

The Polybian Legion

The Polybian Legion was eponymously named after the Greek historian Polybius who described the Roman army during this time period. Some notable changes between the Polybian Army and the Camillan Army which preceded include: Hastati and Principes fought with the gladius instead of the hasta, the Triarii carried the scutum instead of the hoplite shield, and infantry classification was based on age and experience instead of wealth. The Leves and Acensi were also combined into a single class of skirmishers called the Velites.

A Consular Army at the time would consist of 2 Roman legions and 2 Socii (Allied) legions, led by two consuls who rotated command. For every legion that Rome levied, their Latin allies matched it in size. Historically, there isn't any evidence to suggest they fought or were equiped differently from their Roman counterparts. The Socii also brought with them elite troops called the Pedites Extraordinarii who made up one-fifth of their infantry, and the Equites Extraoridinarii who made up one-third of the Allied cavalry.

A typical Manipular legion would consist of 4,200 infantry and 600 cavalry. This meant that a Consular Army of four legions would have a grand total of 16,800 infantry and 2,400 cavalry. Within each legion, the Velites, Hastati, and Principes would number 1,200 each, while the Triarii numbered 600. It really annoys me to see YouTube Let's Players who claim they're using historically accurate armies, yet still recruit just as many Triarii as they do Hastati and Principes. But I digress...

Fielding Your Army

For our purposes, each stack will represent two legions out in the field (1 Roman and 1 Socii). If you choose to fight with a two stacks for a total of 40 units, your composition should look like this:

First Legion

• 1 Legatus
  
• 1 Equites, 1 Socii Equites, 1 Socii Equites Extraordinarii
  
• 4 Velites
  
• 2 Hastati, 2 Socii Hastati
  
• 2 Principes, 2 Socii Principes
  
• 1 Triarii, 1 Pedites Extarordinarii

Second Legion

• 1 Legatus
  
• 2 Socii Equites, 1 Socii Equites Extraordinarii
  
• 4 Velites
  
• 2 Hastati, 2 Socii Hastati
  
• 2 Principes, 2 Socii Principes
  
• 1 Triarii, 1 Pedites Extarordinarii

Notice how both stacks add up to only 18 units, leaving you with 2 open slots to fill. This gives you the freedom to recruit specialist/mercenary units into your army. Incidently, the Romans also started to implement them during this period. After suffering several defeats during the 2nd Punic War, the Romans began hiring specialist troops like the Numidian cavalry and Cretan archers to make up for some of the legion's shortcomings, so definitely feel free to make use of these open slots.

If you choose to fight with a single stack of 20 units, your composition should look like this:

• 1 Legatus
  
• 1 Equites, 2 Socii Equites, 1 Socii Equites Extraordinarii
  
• 4 Velites
  
• 2 Hastati, 2 Socii Hastati
  
• 2 Principes, 2 Socii Principes
  
• 1 Triarii, 1 Pedites Extarordinarii

This will give you a total of 19 units.

Deploying the Legion

Traditionally, the Socii were deployed on both flanks while the Romans fought in the center. Likewise, the Socii cavalry fought on the left wing while the Roman cavalry fought on the right.

I usually deploy my legions in three separate lines in a checker board pattern called the quincunx. The Hastati would form up in the first line with gaps in between each maniple, the Principes in the second line would cover the gaps of the Hastati, and the Triarii would cover the gaps of the Principes. I often deploy my Velites in the very front of my army or on my wings between the infantry and the cavalry.

The Socii also had a tendency to field more cavalry, often outnumbering the Romans. A consular army of this size would have about 1,800 Socii and 600 Roman Equites. Due to the 3:1 ratio we are playing with, I throw my general's bodyguard and Roman Equites on my right wing to create a contingent of 200 horsemen. My other general's bodyguard and Socii Equites deploy on my left wing to form 600 horsemen. If you're wondering why I don't put my generals behind the main infantry body, traditionally the consul in command of the army that day would be on the right wing while the other was on the left. If you only have a single stack, you won't be able to recreate this.

Unfortunately, Rome 2's default deployment doesn't let us deploy this way and DEI's triplex acies formation is currently bugged due to the way units are classified. Rome 2 also deploys your infantry in solid lines so you have to manually space out your units if you want to accurately recreate this formation. This often becomes a tedious and time consuming task.

This image does a pretty good job of illustrating the quincunx:

On the Battlefield

Skirmishing Phase
The Velites are going to be your primary skirmishers. Use them to screen the advance of your Hastati or support your cavalry on the wings. I often split them up into separate groups in order to perform both roles, especially when facing enemies with a superior cavalry force. After both armies are done skirmishing, retreat your Velites through the gaps of your Hastati and reposition them on your flanks.

Engaging with the Hastati
Once your Velites have made it through, your Hastati should form a solid line. That means no gaps should exist between you and the enemy! I see a lot of players engage the enemy with gaps inbetween their Hastati. Not only is this historically inaccurate, it also leaves the flanks of each maniple wide open to attack.

The only instance where I would not suggest forming a solid line is when a full frontal engagement would be suicide. For example, the Romans defeated the phalanx armies of the Successor States by outmaneuvering them. Utilize the tactical flexibility of your maniples in these situations.

You should seek to exhaust and dwindle down your opponent's numbers with your Hastati. They're not expected to break the enemy lines. Once your Hastati are tired or have taken too many losses, pull them back behind your Principes.

Engaging with the Principes
Retreat your Hastati behind your Principes like you did with your Velites.

Principes are the ones meant to break the enemy. They fight in the same manner as the Hastati, but are tougher and have better armor. Most importantly though, they are fresh while your opponent's troops are hopefully tired. If they fail to rout your enemy, pull them behind your Triarii.

Falling to the Triarii
At this point, you should know if the battle is won or lost. Historically, the Triarii didn't do much of the fighting and supposedly rested on one knee for most of the battle.

However in times of desperation, the Triarii were expected to cover the retreat of the army or hold out long enough for everyone to regroup. When you call upon these guys, know that you are commiting one hundred percent of your forces. Best of luck!

The Equites
The role of your Equites is to protect the wings of the army while the main infantry body is fighting. Use them to engage the enemy cavalry, harass skirmishers, and run down routing units.

When fighting superior cavalry, I almost always back these guys up with some Velites. Their javelins should wreck havoc on even the heaviest of cavalry if positioned correctly. They also have a pretty decent charge if you manage to get behind your enemy's infantry.

Pulling Back Your Troops
Ancient battles were more about physically and mentally exhausting your opponent than they were about killing. The rout is where most of the casualties came from, not the battle itself. We know that there were periods in which both opposing sides would pause and regroup before fighting again. Fresh troops would usually be sent in at this point, and those who just fought would rest.

Unfortunately, Rome 2 does little to simulate this aspect of ancient warfare. Pulling out troops already engaged in a fight usually results in the unit taking massive casualties. Since there is no option for an organized retreat, I usually charge my Principes into the fray and then pull out my Hastati. Realistically this wouldn't be feasible and would probably look like a cluster ♥♥♥♥, but it's the best we've got.

There also isn't a point in funneling troops through the gaps of your maniples. Units don't seem to have a problem in this game running through one another's formation so it's really an optional aesthetic for the player.

Conclusion

If you've read this far into the guide, hopefully you took away something new even if it was miniscule. Thanks for reading!

[Vi]

too bad manipular formation is a bit redundant in a game where battles are max 15 mins, even wtih DEI and further battle mods. You're just holding 2/3 of your force back while the entire enemy attacks 1/3 of your army at a time piecemeal.

[Black_Viking737]

Could you create a late republican/early principate army composittion for DEI?

[Lufian]

Would love more of these

[damianvincent]

Great write-up, very impressive and thorough. Thank you for sharing this with us. I especially like how you break down troop numbers for each group. The only thing I might add is making a greater distinction between the pre-Samnium wars Republican Army as opposed to the Post Samnium wars reforms up to the Polybian reforms where the hastati and principes went from using primarily the greek style spear, or hastae, then chancing over to the more historically recognized "gladius". I use quoatations as it would undergo many evolutions itself.

[damianvincent]

Or watch this video: https://www.youtube.com/watch?v=7ESwxQ8WuhY

[Captain Roman S'Jet]

Yes yes, we know, furry.

Spam heavy infantry.

[CptZhu]

due to economic reasons i have to field 19x sicilian levies/mamertine spearmen since they are OP however :(

[CptZhu]

this is epic

[Commissar BS]

Hmm. Not using the Triarii makes sense, probably why I'm running out of upper classes mid game

[Jake]

Enjoyed reading this! Really nice work.