Xjyuk

In this setting, the family unit is based around a clan system. An individual's wealth and status is related to the clan they are born in, and its ancestry is based on matrilineal lines. Marriage does not exist in the form we would recognize. Women remain in the clan they were born into, and support it throughout their lives.

Boys exit their clans upon reaching adulthood. These males leave their families to join small bands of males who live as nomads. Roving bands of these men wander the countryside, hunting and living off the land, moving when neccessary. During breeding season, these bands visit one of these small clans, spend the season, and then leave to go back to their lives.

However, these roving bands can be dangerous. Being made to live off the land, they may be forced to compete with each other for resources. This turns them into seasoned hunters and warriors. Many can see the small clans, made up of women to be easy prey. Some warlord may even decide to join forces and bring many bands together to dominate the weaker clans. Without the equalizing force of technology we have today, this presents a problem.

I need a way to make this viable so that it is actually possible to make this happen in the ancient world. Religion is always the go-to answer for why people do things, but that doesn't seem enough in this case for partial reasons. What set of circumstances would I need to introduce in order to make this culture and way of life stable over the long term?

Three pieces of tech that have been protecting humans from other humans for 5000 years.

1. Hill forts.

https://www.thefield.co.uk/features/iron-age-hillforts-21556

The women live on fortified hills. They can see people coming from a distance and they watch. It is a costly endeavor to try to storm one of these hill forts because the women are good shots and they have a lot of arrows. And poison.

2. Dogs.

These semi-feral dogs live in the fields around the fort. The women encourage them and feed them, sometimes. The dogs keep out herbivores. They also keep out men.

3. Better the devil you know...

The men are no dopes. When it comes breeding time, they know what is up. A band of men will stake out territory in the countryside around a given hill fort. If some other band shows up to get in position, they will have to fight for it. The local band is a known quantities to the women, and these locals do not want to screw up the good thing they have going. They are going to respect the ladies and their system and in turn they get let inside the walls once a year. Random dudes in the hinterlands are out of luck.

If a serious band of marauders does show up and overpower the local band, surviving men will head for the hill fort. They have to get past the dogs, but if a couple of the regular guys show up with their tails between their legs, the women will know to light the fires and get ready.

The way you describe them sounds like this is a hard-wired, bred-in bioevolutionary situation.

I would posit that the females of this race, being left otherwise defenseless, will do what females must. They will be their own warriors, their own hunters, their own watchmen, their own scouts.

I would suspect that because of their biology and their social wiring, males have no interest in females except during the mating season. Once the girls' pheromones wear off and pregnancies are ensured, that's the last they'll see of their boyos until next time. It may be that, perhaps unknown to the females, their males kind of look after them from a distance. They may not live in one community, but these associations of males may wander from place to place in a broad territory that encompasses the smaller territories of their females.

If we assume that we are speaking about humans or a sufficiently similar species, I can imagine one way that can be achieved comparatively easily.

Whether you want to implement it would depend on the degree of cynicism and brutality you want to have in your setting.

It's a primitive, but a pretty effective practice of population control that archaic societies actually often employed - castration. It's pretty horrific, but not much more then female circumcision that is still practiced in some regions.

The eunuchs would then stay in the female villages, and the proportion of villagers to rowing males would be quite far from natural 1:1. The precise proportion of men who are cut to those who are left whole can also be different, depending on the result you want. If you want the maximum genetic diversity with the minimal number of males, they would banish the firstborn son of every woman at puberty and cut all subsequent ones.

The cultural attitude to such practice and the attitude of eunuchs themselves can also be quite different. On one end of the spectrum, they can be treated as property and traded between clans (as women sometimes were, historically) - then you may have a pretty disgruntled portion of population. On the other end, especially if property and status are family matter and not individual, they can stay with their mothers and sisters, working to improve the position of the family and getting privileges from that themselves. In that case, eunuchs can actually count themselves more lucky then those 'whole' males that were banished to the wild lands in puberty. In that case, most of the people in this society won't even think there's anything obviously wrong in their arrangement.

Assuming that (1) we are speaking about humans and (2) by "ancient world" we are to understand the historical ancient world, that is, no pre-historical hunter-gatherers, then the way of life described in the question can be made stable over the long term, but probably not as the querent envisioned it.

The problem comes from the huge disparity between the population densities of a settled agricultural society and a dispersed hunter-gatherer society.

Since the question speaks about the ancient world we must assume that the matriarchal clans are settled in villages or towns and practice some sort of agriculture. This enables them to reach reasonably high densities and total numbers of inhabitants. But then the question says that boys are expelled at 12 or 14 years of age (when they "reach adulthood" according to ancient conventions) and go to live from hunting and gathering. This has the immediate consequence that most men die young, and thus in the world of the question there are many more women than men. And those males who don't die young must by necessity live in very small groups scattered far and wide, for the hunter-gatherer lifestyle cannot support dense populations.

Moreover, the hunting and gathering men cannot possibly be "seasoned warriors". Fierce brawlers, yes, quite possibly. Fearless fighters, acceptable. Seasoned warriors, nope. War as practiced by half-starved hunter-gatherer barbarians is simply not at the same level as war practiced by civilized settled societies.

So in the end the civilized women can easily fend off attacks by the barbarian men. Women have numbers on their side, they have actual military formations and tactics and discipline, and they have fortifications. How do I know that they have fortifications? Because everybody had fortifications in the antiquity. Even a ditch and an earthen rampart, what the Romans called a vallum, are force multipliers. (Fun note: the English word "wall" comes from Latin vallum, an earthen fortitication consisting of a ditch and rampart. A proper wall is murus in Latin.)

All right, so the barbarian men are too few, too dispersed and too barbarian to pose a significant threat to the civilized women. What can be done to make them more fearsome, while preserving as much as possible from the premiss of the question?

Simple. Ditch hunting and living of the land and make them nomadic pastoralists.

Nomadic pastoralism was indeed a well recognized way of life in the antiquity, and not only. Some cultures, for example the Lapps and the Mongolians, preserved it well into the modern age.

Make the sexual division of labor in this world more pervasive than in our real history: have the women labor the land and grow crops, while men roam the wide plains with their herds in search of pasture.

Such an approach would naturally lead to the conflict between tribes of nomadic pastoralists, reminiscent of the range wars known from American westerns; it would also naturally lead to conflict between free-roaming open-range pastoralists and the settled crop-growing women.

• But in this case, wouldn't women (smaller, physically weaker, etc. stereotypes) be certain to lose? No. The settled women would still have an advantage in numbers, albeit smaller than in the case of confronting scattered hunter-gatherers; they would still have an advantage in culture and discipline; they would still have fortifications.




• But didn't the nomadic pastoralists Mongols conquer the world? Well, they did indeed conquer a lot of land, which then they promptly lost. We will never know what would have happened in the end if the Mongols had persisted in their invasion of Europe; I for one think that they would have been beaten even if they had not decided on their own to abandon the attempt. Anyway, better to have those feminine settlements be somewhere not in the featureless boundless steppe.

Nitpicks:

• "Breeding season": humans do not have a breeding season. Better make the sexual congress take place in the autumn, after the crops are gathered and everybody feasts.




• "Some warlord may even decide to join forces and bring many bands together to dominate the weaker clans": and what's keeping the settled towns from banding together to defend their lands? That's the ancient and time tested response to external threats: form a confederacy, a kingdom, an empire. The plucky warlord will realize that what he has done is piss off the mighty Empress of the Fertile Valleys. The bards sing to this day the heroic feats of arms seen in the epic battles.

The Women Are Amazing Warriors

Every female is trained from a young age to be a warrior. They are strong and have an organized military system, like Gengis Khan's:
There's a group of ten soldiers in which the leader was chosen by vote,
There's a group of ten groups of ten soldiers with 100 women in which the leader was chosen by vote,
There's a group of ten groups of ten groups of soldiers with 1000 women in which the leader was chosen by the leader of the clan.
Of course, as you said they are small clans, you can make the number of soldiers of each group lower, but this is up to you.