How can tribes consistently defeat imperial armies?

Question

The Daevanum Empire has many times tried to put an end to the Reuvic raids in their borderlands. Despite being by no means a sick empire (most crises that historians point as the cause of their failure actually were results of the defeats), the empire has consistently being defeated in all campaings against the reuven people.

And worst of all, those are generally not even that close fought! In all but three of these wars, the result was massive raids against the empire's heartland and/or prosperous provinces. Somehow, these tribes have more often then not beaten well-provisioned, trained and experient professional soldiers, as well as the well-educated commanders that lead them.

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These tribes do have a few things in their favor:

• Their society, while tribal and politically divided, is extremally cohesive. The moment that a outsiders threatens even a minor tribe, suddenly the tribes gather to elect a war-king and start acting like a nation-state.

• Their terrain do put a strain on logistics. So they have it easier while defending their own lands, but it does not explain how they keep hitting back at the empire in their own territory

• They have technological parity with the empire, and their economy its not that bad. Between self production, trade and raids, they are about as well equipped as the imperial soldiers. Both the empire and the tribes have about the technology of the roman and parthian empires.

• They are primarily sedentary herders, but with a "nomadic tradition", they have pemanent settlement, but will temporarily move if needed. I think this might help as you can move your flocks to safe/hidden places, while grains in the field can be burned by enemy troops.

• Their culture is quite focus on war, if something is compatible with their lifestyle and would help in a war, they will try to do it. This does not apply to political centralization and greater intertribe cooperation when at peace.

• They usually can fill a bigger cavalry than the empire, but no steppe nomad levels of cavalry. They have horse archers (mostly from their tribal nobility), which the empire lacks.

However, none of this gives the discipline needed to beat an army. Most engagements between tribal armies and professianal armies (that I am aware of) are won by the professional due to the tribes panicking and rooting while the professional could keep it together for longer, such as reserves engaging rather than fleeing when a flack its about to break, or breaking formation to persue the enemy and being crushed by the reorganized enemy troops.

The problem is that this less disciplined way of fighting generally is what makes sense in tribal warfare, as they usually don't use forces large enough to make individual skill less valuable than discipline and army cohesion. On top of that, tribes usually lack the economy to wage long periods of warfare or keep armies well supplied, meaning that they generally will rush to the engagement while they still have the resources to do so, which gives the empire a huge strategical advantage.

My first though was: "Well, nomadic tribes conquer empires all the time, it can be that hard". But the nomadic people advantages that my tribes lack, namely being nomadic make so that there is no important settlement for your enemies to seize and force a surrender (and also obscene amounts of horses). Besides, the occasional tribes conquer big empire in history usually coincide with the empire already colapsing due to other factors, while the Daevan-Reuvic Wars always start with the empire on offensive, thus bound to not be near colapse every time they try.

How can the tribal people overcome these problems? Can they find a way of fostering discipline and unit cohesion in their warriors or better feeding their armies? Or they can only try to go around this problems? What strategies or tatics would give them a edge over a better organized force?

Answer 1

No Mystery:

There's no mystery why the empire repeatedly loses wars to the Reuvics. The Reuvics don't have anything that's worth the empire taking away from them. They also live in a large, open area without extensive sea access. The Reuvic economy depends on goods stolen from the empire to operate, because it's so poor. The Empire can invade their territory, and they simply melt away. The Imperial supply chain gets attacked continuously, while the Reuvics burn their towns and crops as the empire advances. The Reuvics give the empire no fixed battles to fight, or giant castles to besiege. The more soldiers the Empire sends into Reuvic territory, the fewer are guarding the empire.

While the cat's away, the mice will play.

Your Reuvics don't rush to costly battle, but rather to profitable raiding. And if the Reuvics are internally cohesive (and already have a taste for stealing from the much wealthier empire), then every time the Empire invades, the tribes go on the offensive. The first cut of the loot is to pay back those whose assets are destroyed in the Imperial invasion. This means those who burn their crops are wealthier after the war than before. Those seeking to profit from these giant raids don't care if the empire is degraded, they just want profit and revenge.

The Empire can CLAIM to be victorious, but there's nothing in Reuvic territory worth holding. Attempts to build forts to secure the territory just result in a slow bleed to the Imperial economy as every supply shipment is attacked. Inevitably, the large cohesive Imperial units are never given a proper target to engage. So it's better for the Empire to guard against attack, suffer low-level losses, and have an excuse to maintain a large standing army despite the demands of the wealthy to cut back on military expenses.

The only sustainable way to stop the raids is to hire Reuvic mercenaries to defend the borders. Only problem is that the moment you stop paying them, they are armed, unemployed men you helped train with a taste for Imperial goods sitting on the border.

Didn't we stop maintaining our own imperial army so we could afford to employ all those Reuvic mercenaries?

Answer 2

I think that you already have many ways to justify the tribes beating the empire - I was going to point to terrain as one of the best advantages. It's what helped America win its independence, but then suffer in Vietnam nearly two hundred years later.

Some further furnishing of your worldbuilding - a trap of discipline might be adhering to military traditions that are a fallacy. Perhaps the empire's troops suffer because the generals stubbornly assert that war should be done in a gentleman like way, everyone in neat little lines, taking turns attacking, while the tribes don't really care, and engage in aggressive guerilla tactics.

As with so many things, extrapolating little details helps make the worldbuilding much more rich and nuanced. Think of how little stupid decisions, like the adoption of a bad military tradition could cause problems.

It also should not be understated the power of fear. A well understood tactic in the history of war is to make your enemy fear you. Consider things like the rebel yell in the Civil War. Not only does it make your own forces feel more unified, but it can fill the enemy with sheer dread - that could be something that shakes even the most disciplined empire soldier.

Answer 3

It all comes down to leadership. Ghengis Khan didn't just take a bunch of tribesmen and beat everyone in sight. He took a bunch of tribesmen gave them absolute discipline, changed their way of fighting and organisation and then beat everyone in sight.

It wasn't just the horses, or the bows. Mongols and others had those for a long long time and never got further than killing each other.

So your people need a hierarchy similar to some of the Greek and Roman ones. In times of crisis a leader or a couple of Consuls are put in charge and given absolute authority and martial law. They then had a force with a single leader with the single agenda of overcoming the crisis. Facing them were multiple leaders with multiple agendas.

In your case it's a single force with a single language and culture focused on one mission, rather than an empire with perhaps more than one and many different agendas.

The weakness of tribesmen type cultures has never been the fighting men. They're experienced hunters and warriors living hard lives. The weakness has always been leadership. Any time great leaders arose they caused havoc. The Huns bought both Roman empires to their knees. The Mongols hunted armies like they were animals.

Answer 4

First: Trade and Commerce

One reason could be influenced by and trade with another culture. Societies don't exist in a vacuum, and there isn't a reason why there couldn't be another mythic, in the empires eyes, culture beyond the borderlands. Nomadic culture are known for trade, particularly because they move around a lot. There are a number of ways this could come into play.

1. They could have technology and equipment the empire doesn't have access to.

2. They may have leader trained in another culture's warfare.

3. They may have direct assistance as a proxy.

Second: Exiles and Criminals

Another is exiles from the empire. They would know exactly how they fight and adapt to it. Criminals such as smugglers could know all the routes around the area and which local military officials are corrupt enough to bribe.

One could also look at the Cassocks.

Third: Official Incompetence

That front could be the dumping ground for the empire, while the competent could be sent elsewhere, even as home guards. Imperial citizens loyal to that culture group could sabotage supplies and such. And the officers may simply be incompetent due to selection process or a corrupt promotion path.

Answer 5

Two Reasons

Firstly geography and climate. The Empire developed in and largely encompasses one 'corner' or part of the continent they share with Reuvic. That portion is bound on 2 or 3 sides by sea and/or mountains etc. For the most part the Empire is well watered and the soils along its coast and the river valleys that drain from its hinterlands into the sea are highly fertile. All of which lets it support a large (and for the time period) highly urbanized population. Most trade into or out of the Empire either travels by sea or has else has to pass through Reuvic lands.

As a result the bulk of its army are, like the Romans and Greeks massed infantry (think dense masses of pile or spear and archers, supported by a smaller proportion of horse drawn from the rural nobility etc etc.

The Reuvic on the other hand live on the the one open flank the empire could expand out into were they not in the way. And that terrain turns into broad open steppe ideally suited to herding and ranching but much less so to farming because the prevailing winds and climate means the step is dryer and colder for large parts of the year than is desirable for agriculture. It also provides excellent trade routes to other parts of the continent. Lastly their territory is huge and basically doesn't end until geography and climate causes it too i.e. the stepes end.

Result? The Reuvic have developed armies almost entirely centered almost around mounted warfare. (Although they are wealthy & experienced enough to hired skilled siege engineers or other specialists when needed.)

2nd Point? Empires don't exist in a vacuum. There is no permanent state of war between the two sides. Conflict may spring up every generation or so but outside of those periods goods and people cross the border regularly. There is a degree of intermarriage and people in both empires including merchants, diplomats and soldiers etc have been exposed to each other's culture. It is inevitable then that over time the Reuvic will become familiar with Imperial military tactics and organization both by direct observation and from reading texts on the subject. Likewise the Empire will become familiar with their opponents.

The best chance for success ?

For the Empire? The sheer cost of trying to conquer that much territory outweighs any benefit. Therefore try to sow disunity amongst the Reuvic by favoring some tribes over others via diplomacy/gifts and trade concessions etc. Then fortify all the choke points and natural barriers along the the main invasion routes used by the Reuvic in depth. Also fortify the towns and cities along those routes and mandate that provisions to sustain the population be stored in event of siege. Create militias to hold the towns and cities if necessary (assuming the population is loyal) and train your armies or at least the officers in Reuvic tactics, especially your cavalry. In short make invading not worth the cost for them to. And if they still invade and you see an opportunity stage brief counter raids with your own trained light cavalry into their territory at points along their border where their army is not massed to distract them.

For the Reuvic? Have the war leaders study or be advised on Imperial military tactics, logistics and organization. Hire experienced soldiers from other parts of the continent as instructors or even better ex-imperials. Get a tribal consensus on which military policies should be adopted to counter the Imperial army and have each tribe train and organize their warriors accordingly. Finally stage large scale unit maneuvers etc far away from prying Imperial eyes to test them out. And build up an intelligence network inside the Empire.

And of course you should read up on the Roman and Mongol armies.