Luzula

Posted by Bret Devereaux

https://acoup.blog/2026/06/05/collections-pre-modern-armies-for-worldbuilders-part-i-why-they-fight/?utm_source=rss&utm_medium=rss&utm_campaign=collections-pre-modern-armies-for-worldbuilders-part-i-why-they-fight

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This week I want to try something a little different. Rather than taking apart a particular fantasy military system, I thought I might try to lay out a more general sense of how military systems tend to map on to societies, both because such general historical frameworks are handy for thinking about the past, but also because they make useful rules of thumb for imagining fantastical societies. So essentially here we are asking: how do societies end up with the sort of armies they have?

This is going to take a few posts to get through because there are actually quite a few key components to cover: the why and how of recruitment (both ‘why do these people feel obligated to serve’ and ‘how do you get them into the army’), how a society pay for that (or doesn’t), who leads it and how, and how once formed any army coheres in the field. Finally, we’ll wrap up with some historical ‘archetypes’ to show how these different facets link together with the underlying civilian society and also how that shapes what they look like on the battlefield (including weapons and tactics).

This series is also going to be a bit unusual because in some ways its purpose is to link up and summarize a bunch of other posts. We’ve had a lot of posts and series over the years which examined this or that historical or fictional military and discussed the ways in which their militaries reflected civilian society and I wanted to pull a lot of that together in one place. As a result in this series – more than most – the links are going to be ‘load bearing.’ Likewise a lot of the heavy bibliography here is going to live in the links, although I think for someone looking to get a handle on how pre-modern societies and pre-modern militaries come together, the two key readings I would suggest are P. Crone, Pre-Industrial Societies: Anatomy of the Pre-Modern World (1989) and then J. Landers, The Field and the Forge: Population, Production and Power in the Pre-Industrial West (2003). Also well worth reading as an overview is Azar Gat, War in Human Civilization (2006).

Now we’re going to restrict ourselves a bit here in that we are going to stick to pre-modern or more correctly pre-industrial armies. The rules change a lot for industrial and post-industrial armies, though by the same token we really don’t have nearly the same range of examples for industrial armies either: we really have a single dominant model for industrial armies that emerged in Europe from 1914 to 1945 and then a bunch of reactions to that model (along with what we might term an industrial ‘transitional’ period from ~1800 to 1914). It is thus hard to build a complete typology, because the industrial sample size is so small.

By contrast, the sample for pre-industrial agrarian armies is really big, so it becomes a bit easier to spot recurring patterns of organization and structure as different societies stumble on to the same solutions for generating force. So that’s what we’re going to do this week: look at some of the patterns, keeping in mind that these are general rules with many complications and exceptions. In the process, we’re going to pull together a lot of the individual discussions of specific systems – historical and fantastical – as examples.

Fans of fictional worlds will have often run into the most egregious examples of the failure to think in these terms. Professional or seemingly professional armies employed by societies that lack the administrative structure to manage them, armies that are too large or too small for their parent societies, ‘guards’ that seem to spring out of holes in the ground rather than organically fit into society anywhere and so on.

But first, as always, recruiting and maintaining large pre-modern armies is expensive! Much like many of those pre-modern armies, this project is supported by devolving the costs of my ruinous book-buying habit on to recruits readers. You can help by spreading the word to new readers and by supporting this project over at Patreon. If you want updates whenever a new post appears or want to hear my more bite-sized musings on history, security affairs and current events, you can follow me on Bluesky (@bretdevereaux.bsky.social). I am also active on Threads (bretdevereaux) and maintain a de minimis presence on Twitter (@bretdevereaux).

Armies and Societies

I have written this maxim a few different ways, but it is worth writing again: no army can help but recreate its civilian social structures on the battlefield.

When analyzing a historical army or creating a fictional one, everything must begin with that idea, that military systems grow out of and reflect their ‘civilian’ societies or – for societies that lack civilians as such – reflect the civilian side of the lives of their members. That means that armies tend to recreate civilian hierarchies, with similar – often identical – lines of status between the two.

So to understand what kind of military our society might come up with, we first need to ask some key questions about the civilian society.

First: is this society agrarian? Which is to say, are they farmers? In most cases, the answer will be yes because with only a handful of exceptions, if they’re not farmers you’re not going to have cities or states and most settings have those. That said, if your society consists of nomads – either hunter-gatherers or pastoral nomads – they aren’t going to have a state (which is a creature of the agrarian world) and so you want to think about non-state forms of military organization, which is going to channel them towards some specific solutions to our problems below.

Next: is this a state? Is military force in this society collected into a single political entity or is it fragmented among many different centers of power? One odd choice I see in a lot of fantasy settings is to have huge, sprawling cities with non-state systems of organization (power informally divided among a bunch of different groups that all wield force), but that’s not a pattern we see often historically. Instead, the more urban a society is, the more likely it is that military power is concentrated into a single political entity – the state. At the same time, non-state polities may lack a single political entity with a monopoly on the use of force, but that doesn’t mean they lack a military system, it just means that power is fragmented in that system.

Third: what kind of aristocracy does this society have? Every society has a socio-economic elite, but there are different kinds. Does aristocratic wealth mostly flow upwards from large landholdings or flow downwards from employment in a royal bureaucracy (the former is much more common)? Likewise, to what degree does this society have a bureaucracy as such and how much power does it wield? It can be easy to assume modern bureaucratic administrative structures, but these are rare in pre-modern societies: power is often wielded by local grandees than by employed representatives of the state and if the power is wielded by those grandees, the military system is likely to run through them to some extent as well as well.

Your aristocrats are going to assume that – since they lead society in peace – they lead society in war, but how they do so depends on their self-conception. Here, I distinguish sometimes between military aristocrats – aristocracies who understand their primary purpose is warfare generally (often leadership), as distinct from religious or bureaucracy aristocracies that might be of a non-military character – and warrior aristocrats, who understand their primary purpose in society as personally fighting in a specific way (usually but not always mounted).

Note that while warrior aristocrats’ legitimacy in claiming aristocratic status comes from their personal practice of violence, the source of their power is almost invariably wealth from large landholdings: they’re not aristocrats because they’re good at fighting. Instead, they’re aristocrats because they’re rich and then to justify the wealth and power they wield, they practice a certain form of direct, personal kind of warfare. A guy who is really good at fighting but is poor and without title is not a knight; a guy who has wealth and title but is terrible at fighting is a bad knight, but a knight nonetheless. Warrior-elites are thus elites-who-are-warriors, not necessarily warriors-who-are-elite-at-war, though since their social class places a lot of emphasis at being good at fighting, they’re often very good at fighting (in a specific way, again, usually but not always mounted).

Fourth: how do the regular farmers (who are 90+% of the population) connect to the aristocracy? Are they mostly free-holders who own their own land, but are economically dependent on the Big Man? Or does the local Big Man – that is, the aristocrat who is nearest them – own their land itself? Or does the king (or state, in some other form; it might be a temple!) own their land, in which case the aristocrat they engage with is an administrator rather than a land-owner?

For the aristocracy to exist (and for the state to exist, if it does), it has to be siphoning agricultural production from these smaller farmers, so consider how that happens as well. Aristocrats collect rents on the lands they own or control. The state may collect taxes, but in many pre-modern states, royal revenues are dominated by the lands the king owns rather than taxes. Naturally, if taxes are being collected, that implies some kind of bureaucracy collecting them, which non-state societies may not have and which may be underdeveloped in weak-state societies.

What we’re trying to get with all of these questions is thinking about how the peasantry and the aristocracy relate to each other and how that relationship is understood and justified. Those questions are important because civil society comes first – armies are built out of existing subsistence systems and social structures, not usually the other way around – and because the structure of a society limits the possible military systems it can house.

Recruitment Principles

Once we have a sense of our civilian society, the next thing we need to think about is how do we get recruits?

Landers (op. cit.) breaks down recruitment systems based on the principle they function on, distinguishing between general compulsion (conscription by force, levies), the entitlement principle (service as the flip-side of the coin for some set of rights or status), the vocational principle (standing armies or military aristocracies that served because that was their role in society) or devolution (devolve the problem downward onto vassals, communities or households). That’s a useful framework, but I want to shift it around somewhat for our purposes, because I want to separate clearly why the recruits fight from how you get them (and because I think ‘general compulsion’ is actually not the most useful category here).

So we can start with what I am going to call the recruitment principle (as distinct from the recruitment method), which is the why of your recruitment: why do these fellows feel like they must or ought to serve. A lot of historical fiction or fantasy settings fail to address this particular question or else answer it with a very crude ‘because they have to’ (that is, compulsion) but that’s not usually how this works. After all, this society is about to give these fellows weapons, so without some broader social structure that encourages or constrains them to remind at the standard, there is very little preventing them from deserting or revolting. Compulsion can get me into the ranks, but it struggles to keep them there.

The first place most modern folks’ mind goes, of course, is to pattern this task off of their own jobs and so to assume that these fellows are under arms because they are paid to be, which I am going to term the employment principle (separate from the vocational principle). We may sum it up with, “recruits show up purely as an economic transaction: service for money” – it’s a job. These may be foreign troops (in which case they’re mercenaries) or domestic troops, but the key thing here is that the bond which holds them to the army is monetary: they get paid.

The problem is this is not actually the most common recruitment principle. Indeed, while many armies may employ mercenaries as auxiliary troops or maintain some small standing employment-based component (like non-noble professional retainers, for instance), it is fairly rare for pre-modern armies to function purely ‘as a job.’ The exceptions are professional armies, but professional armies are the exception, not the rule: the later Han dynasty, the Roman Empire (but not the Republic) and early modern Europe feature professional armies, but otherwise these are uncommon. Crucially – and we’ll come back to this as we move along – professional armies require a strong state with a capable bureaucracy and extensive revenues, because the state is taking on the whole administrative and financial burden of maintaining the army. Early modern European states famously struggled horribly under those burdens, while the Roman Army of the imperial period consumed well over half of the state’s budget.

Note that warriors and soldiers recruited by other principles might also get paid (although often not as much), the difference is that there is some other social connection that is underlying their recruitment.

Instead, it is more common that the core of military forces in pre-modern societies arise out of three basic sets of principles (two of which I am borrowing from Landers): the entitlement principle, the vocational principle and what I am going to call the clientage principle. All three share an element in that what ties an individual to recruitment is who they are which in pre-modern societies that are generally extremely low social-mobility societies, is almost invariably a product of what family they were born into.

In entitlement principle recruiting, liability for military service is an expectation that corresponds to a set of social rights and privileges, most often citizenship. Note that we’re not talking about citizenship as a reward for service, but rather service as a requirement of citizens. Naturally, for an entitlement system like this to really function, there needs to be some socially valuable position, with connected rights and privileges, available for common folk (we’ll talk about aristocrats in a second). That tends to make entitlement principle service a creature of smaller citizenship-based communities: A Greek polis recruiting hoplites, the Roman Republic recruiting its legions, or medieval town and commune governments establishing a service requirements amongst the townfolk (the burghers), whose citizenship in the town marks them apart from the regular peasantry.

The great advantage of entitlement principle systems is that, because social status and military service are tightly interconnected, getting soldiers to muster and keeping them in the ranks is relatively easier. Think about a Roman citizen soldier in the Middle Republic: if he deserts, where does he even desert to – his hometown where everyone knows he’s supposed to be with the army and where he and his family’s entire social identity is tied up with his liability for military service? The system creates really strong social pressures that make this easier.

The limitation of such systems is that they require that entitlement in the first place and that entitlement almost always comes with the expectation of a political voice through some kind of voting or communal consensus decision-making. That may not sound like a tradeoff to you, but it certainly is to the elites of this society: to recruit on this basis they have to cede power to the commons to some degree in order to create the political entitlement worth fighting for. In practice, it should be noted, the systems don’t generally seem to form that way: they are not grants from the aristocracy to the commons (‘fight for me and I’ll let you vote!’) but rather concessions wrested from the aristocracy by the commons through collective action (‘let us vote or we won’t fight!’), which then acquire the heavy reinforcement of becoming the traditional rights and privileges of the citizenry.

The next option is what we can call (following Landers) the vocational principle, which also connects service to who you are, but rather than connecting it to your place in a political order, it connects service to a place in the broader social order: the vocational principle is one in which a certain class of people fight because they are the warrior class, typically because you were born into the warrior class.

The vocational principle can come in two forms. First, in many non-agrarian, (hunter-gatherer or pastoral nomads (like Steppe nomads)), or relatively less complex ‘horticultural‘ societies, it is often the case that the entire free adult male population is part of the ‘warrior class.’ These are, after all, generally very small clan- or tribal-based societies with a lot less social stratification so ‘everybody’ (that is, all free adult males) fights. For men, participating in communal warfare is a core component to belonging to the tribe, camp, clan or village.

The mistake one sees in a lot of speculative fiction (and also certain reactionary political movements) is assuming that this sort of ‘everyone is a warrior’ social structure can be transplanted to more complex societies with greater degrees of specialization. The reductio ad absurdum of this are some portrayals of Star Trek’s Klingons: an entire post-industrial multi-planet empire that can design starships (and so must be hyper-specialized) but where also somehow everyone is a warrior trained in close-combat weapons. Real societies do not train their starship designers (or their blacksmiths) to also be master swordsmen because that isn’t worth anyone‘s time.¹ But they pretty clearly can’t: the moment a society begins specializing its labor (required to achieve high population densities), ‘fighting’ becomes to one degree or another a specialized role too.

The thing is, as we’ve discussed, while non-specialized ‘all warrior’ societies can sometimes overwhelm highly specialized agrarian societies by and large since the advent of farming the most resource-rich parts of the world have been dominated by complex, stratified and specialized agrarian societies, because of their higher population densities – pre-modern agrarian societies can get into the 30-70 people per square mile range, compared to something like 0.5 person per square mile for hunter-gatherers outside of very resource rich zones and something like around 2-5 per square mile for nomadic pastoralists. It usually doesn’t matter if everyone in your tribe is trained to be a warrior if those farmers over there can triple your numbers by mobilizing just 10% of their peasants. There are exceptions, of course, but they’re rare.

Instead in more specialized societies we see the second form of the vocational principle: a warrior class in which a distinct specialized class in society are warriors (or military leaders), usually by birth (because, again, these are low social mobility societies). In essence, this is a case where in the more complex society, just as ‘farmer’ and ‘blacksmith’ and so on have become both specialized jobs and also basically hereditary classes (because who is picking ‘subsistence farmer’ if ‘pampered noble’ is an option?), ‘warrior’ becomes just one more specialist social class, defined largely by heredity.

That can take a number of forms, the most common of which is the military aristocracy. The aristocracy – or some part of it (there may be a parallel civic or religious aristocracy) – has as its justification for its existence that it is the part of society that fights or at least that specializes in warfare. These fellows are aristocrats, to be clear, because they’re rich, not because the fight well – but to be a member of the aristocratic class in good standing with the disproportionate access to prestige and resources that implies also requires being a military specialist and so they develop those skills and are available for privileged military positions (like cavalry or command). We’ll get into, in a later part of this series, the differences between warrior aristocracies and what I’m going to call officer aristocracies (does the noble primarily fight or lead?).

That said, this category also includes some other ways of structuring a military vocation for a society. One we’ve discussed only a little bit are military slaves (like the Mamluks)- a low status class of vocational warriors, though these fellows have a habit of not remaining low-status or slaves for very long, because – of course – they have weapons.

Alternately, conquering empires might seek to create a vocational military class by putting soldiers on plots of land (complete with laborers) in the expectation that they and their children will remain liable for an elite kind of military service. These we call military settlers and they are usually a feature of a regime moving in – societies usually do not impose military settlers on themselves. The ‘Macedonians’ in Hellenistic kingdoms make for a good example of this, as do Arab garrison cities in the Rashidun Caliphate. For ‘everyone is a warrior’ societies that do end up overrunning larger, more complex agrarian societies, this is often what happens: the tribal ethnic group becomes a military aristocracy settled as overlords over the resource rich land of the conquered.

Finally, we have clientage principle recruitment, where the recruiting principle is that the men being pulled into the ranks are – in their civilian society – dependents of the fellows recruiting them. In this case military service is part of the obligations of the dependent towards their superior. That may seem strange in some cases – as a condition of giving the local Big Man a chunk of your food, you also sometimes have to fight for him? – but its important to remember that these societies do not see the exchange that way. Instead, they’d frame it that, as a condition of having the Big Man’s protection and being able to farm his land, you give him a chunk of the produce and are also expected to fight for him. It’s important to remember that these principles for recruitment are not laws about the physical universe, but fundamentally questions of psychology and culture: if the entire culture agrees that the land belongs to the lord or the king or the temple and you are paying (in a way) for the privilege of farming it, then that is the reality for all concerned.

Dependents here can come in a few varieties. The highest status such dependents might be retainers, men maintained in an aristocrats household as full time ‘muscle.’ While these fellows might be paid mercenaries, in a lot of societies they’re not getting paid in cash but rather in status and a living: they get to live as part of the Big Man’s household, they get their food and other necessities and they’re a more important person than the peasantry. Crucially, retainers of this sort are not ‘free agents’ to the highest bidder, but often tightly bound by formal ties (clientage, hospitality, familial bonds, homage and so on) to a specific aristocrat.

Below that, a Big Man might expect that as part of the unequal reciprocal exchange of clientage, his clients – the poor farmers around him – might owe him support which would include following his lead in warfare. At the same time, as we’ll see, we can flip this sort of thinking around and say that for the community, the Big Man forms a natural leader around which the community, if it is under threat, can rally (and the flipside of that, the Big Man is probably a vocational warrior, as above). Finally, the dependents here might be some form of non-free persons – not usually slaves, but rather tenants or serfs. Often the package of obligations these folks owed their overlord included corvée labor of some sort, so military service as such an obligation makes some sense.

We can see these sorts of systems at work with the Carolingian general and select levies or the Anglo-Saxon fyrd. In both the Carolingian and Anglo-Saxon system, there was a ‘general levy’ of all free men called up as a local defense militia, but households were also brigaded together and required collectively to furnish a man for the select levy to provide a standing or expeditionary force. It is striking how these systems required the active participation of local magnates in order to act as focal points for organization and leadership. As a result, these systems tend to be fundamentally local: while the king has the authority to call up a whole bunch of regional select-levies or fyrds to make up a field army, in practice these are local units, not a ‘national’ conscription system. Notably, Charlemagne’s effort to impose a royal bureaucracy on the Carolingian levy using royal officials (the missi, ‘those having been sent [by the king]’) emerges as a kind of last-gasp effort to keep this system running as it comes apart and never quite works as a centralized system.

That said, this sort of system could be centralized and extended to form a ‘national’ conscription system, with the example that springs to mind being the early Han dynasty (202BC-220AD) military system in China, which emerged out of the mass conscription systems of the Warring States period, where very large armies were raised for specific campaigns against peer competitor states. Notably, as the Han dynasty’s primary security challenges lay with holding frontiers (the Qin dynasty having already removed all of the peer competitors before being replaced by the Han), the Han system steadily transformed into a professional standing army composed of a mix of paid professionals and military settlers. That said – and we’ll come right back to this next week – mass conscription requires record-keeping, bureaucracy and state centralization that relatively few pre-modern polities have. Still it certainly is possible to have a society with at least the notion that the common peasant is simply obligated to perform some amount of military service.

Putting Society and Principle Together

So to recap, we can list our recruitment principles with a very rough sense of how common they are and where:

• The Employment Principle (because they get paid): frequently used to supplement armies that have a core recruited another way but only rarely the main recruitment principle. Where it is used as such (professional armies), it requires a strong state with a lot of revenue and state capacity. Examples: Imperial Rome, the later Han Dynasty, some early modern European armies.
• The Entitlement Principle (because it is the converse of some set of rights these fellows have): common for city-states or other sorts of republics, but requires having a legal/political status like citizenship which is valuable enough to fight for. Troops recruited on this principle can be expected to basically recruit and arm themselves in many cases, but they’re ‘paid’ in political rights as much as cash. Examples: The Roman Republic, Greek polis-armies, medieval town militias.
• The Vocational Principle (because it is their social role/class):
  • All-Warrior Society (every free adult male is a warrior): common in largely non-specialized societies – hunter-gatherers, nomadic pastoralists, very early agriculture. Troops recruited on this basis arm, organize and largely recruit themselves, but these societies tend to be small, low population density and comparatively poor. Examples: Plains Native Americans, Steppe nomads, hunter-gatherer societies.
  • Warrior Class or Officer Class (specialized society with a dedicated fighting or military-leadership class): extremely common among complex agrarian societies, a military aristocracy of some sort is practically the default mode of leadership in such societies, but note that warrior-aristocrats and officer-aristocrats may have very different expectations of what that means. Often the fellows provide the leadership for otherwise employment-, entitlement- or clientage-based armies or alternately a core of specialist warriors around which such levies are grafted. Examples: Almost too numerous to provide – non-state Gallic aristocrats, medieval European knights and nobility, the Roman Senate (an ‘officer class’ example!), and so on.
  • Military Settlers (an imposed military aristocracy of fighters given land in exchange for future service): a fairly common solution for consolidating conquest (especially for societies which simply lack the bureaucratic infrastructure for direct governance), creating a new upper-stratum of military-aristocrats that are often ethnically distinct from the ruled. Examples: Macedonian military-settlers after Alexander’s conquests; the garrison-cities of the Rashidun Caliphate.
  • Military Slaves (a subordinate class of specialist warriors): a relatively uncommon and historically unstable system, but hardly an unknown one, heavily dependent on the availability of an ethnically distinct class of warriors available to be enslaved. Examples: Mamluks, Janissaries.
    • We might also put Prisoner Armies (recruitment as punishment for a crime) in this category. These tend to be somewhat more stable, but their military performance is not always stellar. Example: the armies of the Song Dynasty.²
• The Clientage Principle (because it is an obligation they have towards social superiors)
  • Retainers and Clientage (little men have specific ties of loyalty to Big Men who can call them to arms): as far as I can tell, the primary way complex non-state societies raise military force. Because it relies on personal ties, it tends to stay fragmented. Examples: non-state Gaul and Spain, but also vassalage-based medieval polities.
  • Universal Military Service (little men owe military service to their lord, king or the state): common although rarely as universal or centralized as the name implies. Often takes the form of regional militias agglomerated into a larger army (examples: Carolingian select-levy, the Anglo-Saxon fyrd), but there are rare examples of truly mass conscription systems, particularly in China (examples: Warring States period, Qin Dynasty, early Han Dynasty).

What I hope emerges from this quick comparison is how sensitive these principles are to the structure of the underlying society: for most societies, the options whittle down to just a handful almost immediately. A fragmented state with a weak central bureaucracy will almost inevitably need to reply on military aristocrats, their retainers and clients because it hasn’t the revenues or the political structure for anything else, for instance. A society with specialized economic roles isn’t going to be able to set up as an ‘all warrior’ society and a society without specialized economic roles isn’t going to be able to use any other system. A society without a tradition of universal military service is going to have a hard time conscripting its peasantry and a society without a citizenship-like legal/political status is going to have a hard time recruiting on an entitlement basis. Likewise, if a society lacks a large warrior-aristocrat class, then it lacks a large warrior-aristocrat class and cannot recruit on that basis.

Next week, we’ll look at putting these principles into action, thinking about how armies are raised and paid for.

https://acoup.blog/2026/06/05/collections-pre-modern-armies-for-worldbuilders-part-i-why-they-fight/?utm_source=rss&utm_medium=rss&utm_campaign=collections-pre-modern-armies-for-worldbuilders-part-i-why-they-fight

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