• They do not have access to fast and reliable transport options like steam boats, trains and do not use fossil fuel. They can only rely on the power of the winds and water currents for long distance travel. And they could also do it on land of course.
  • Countries can import food but it's much more limited than it is today. Conservation techniques are not as good so you can't trade fruits over long distance for example. Unless they are dried or processed in some way that they can be kept for a moderately long period of time but I don't think it can be a good substitute for normal food.

I'm making the assumption that importing food comes with some risks. The weather can be unpredictable, it is risky also because of war. More broadly, it makes you more vulnerable to others if you depend on imported food. It's still a problem today with food but with other resources as well.

How much of the country consumed food can come solely from importation ? 10%, 20%, 30% ... The imported food can come form another country or another region inside the same country that is far away. Like the Romans importing food from Egypt.

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    $\begingroup$ Do some research on Ancient Carthage...their merchant marine fleet in the Mediterranean pre-BC could have done 100% food imports, though it was never fully required. $\endgroup$
    – Twelfth
    Nov 17, 2014 at 18:14
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    $\begingroup$ Question is not answerable without definition of what is "pre-modern". $\endgroup$ Dec 17, 2014 at 21:34
  • $\begingroup$ It also needs specification on what is meant by "import". You could fairly easily have an independent city-state that gets all of its food from the surronding area, but that area is part of a different (allied) country. $\endgroup$
    – KSmarts
    Dec 19, 2014 at 18:32
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    $\begingroup$ Athens retired behind its Long Walls for years during the Peloponnesian Wars, and then just about all of their food must have been imported. $\endgroup$
    – Oldcat
    Jul 31, 2015 at 20:56
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    $\begingroup$ It depends on just what you mean by "import". Rome the city imported most of its food from Egypt, Spain, and other places around the Mediterranean, but usually they conquered them and made them part of Rome the Empire first. $\endgroup$
    – jamesqf
    Aug 1, 2017 at 18:37

9 Answers 9


This is practically impossible to quantify to 10%, 20% as you write in your question, because even if we had statistics, which we don't, what would be the basis for measurement?

Also, you don't specify what you mean exactly by "pre-modern".

Also, coming at the question as "How much of the country consumed food can come solely from importation?" is not going to have one answer. Even if you could quantify it (say in an abstract simulation or game) it is going to vary a lot by the specific situation. For example, the amount of trade that other places can and will send has little or nothing to do with the population living someplace, other than what they have of value to trade with, and how much food is available domestically - they are all independent variables, and the relationships between them are complex and non-deterministic.

However, I think it's fairly safe to say that before large-scale trade, every people needed to at first get, or be able to get, 100% of its food from its own surroundings. Food that they would want to trade for from someone arriving in a ship would tend to only be things that they did not have, or did not have the same type and quality.

Food and ingredients were traded even by the first traders, however, particularly because some things were scarce or not available at all in the market location, so the percentage consumed of a particular good could be very high or even 100% from trade, unless and until that trade actually allowed the recipients to produce it themselves (via copying, or via seeds or fertile animals, for example), depending on what it was and what the local conditions were. For example, the "Western World" still imports coffee from the few places where it can be grown.


Grains store pretty well (well, considering your other options) - on the order of 20+ years. And can be shipped. Many countries shipped out all of their wheat production in the Middle Ages. And shipped in a lot of meat, for Christian 'meatless' days, which drove a lot of shipbuilding and fish-catching - as well as fish-drying.

Most countries didn't get to 100% sustainable, because they never needed to. And when trade was cut off, or crops failed - large swaths of the population died or migrated. That's why one of the four horsemen talked about in the Christian Bible is famine. A routine part of life back in the day.

Fruits are not the basis of anybody's diet.

Probably of more interest is going to be protein and fat trading. Read: dead animals.

Most people, in most of the past, have lived mostly on grains; typically one of the big 3: wheat, rice or corn. All of which ship well. Very few people (royalty/rich), since the advent or agriculture, have had varied diets.

The other answer is correct: define pre-modern; and hard numbers (or even guesses) are going to be hard to come by. If you want some Middle Ages reading, go to Braudel.

If you want an example of modernity, look to Nauru - who were going on 100%, mainly because they were rich enough to do so. If your country is rich enough, you can get lots of things done... but the problem with that is the same thing that happened in Spain after the new world gold/silver influx happened - nobody wants to do any work. And that's unsustainable in the long-term.


As the question says, it is impossible to have a hard and fast answer. However, here are a few factors to consider:

  • Production capacity and population. A city-state without any farmland of its own might be almost totally dependent on food imports. An example would be early medieval Venice, which could catch its own fish from the sea but otherwise imported practically all of its food. On the other hand, medieval England was more or less self-sufficient in food, so it only imported luxury items.
  • Transportation and storage. Without modern refrigeration, things like grain, hard cheeses, preserved meat and fish, wine, or olive oil can still be transported long distances. Fresh vegetables, meat and milk are impossible to store for more than a day or so. If you want to move fresh meat long distances, it is much better to transport the live animals and slaughter them at your destination. Moving goods by water (canals, rivers, seas) is generally much faster and easier than by land.
  • Wealth and organization. Moving large quantites of food long distances implies a well-organized government like ancient Rome. Impoverished societies may be unable to pay for food from their wealthy neighbours, even if the food is available -- see the Irish potato famine for a historical example.
  • Political considerations. Because of political, military, or cultural factors, a country might choose to import food from a more distant location instead of nearby.

The answer to the question is that a pre-industrial country can import all of its food. The ability to import food is not meaningfully limited by technology. It is just a matter of building and maintaining the infrastructure. You need functional sailing ships, good harbours, and good roads. Granaries and ceramics too, but those usually precede the technologies I mentioned before.

However the ability of pre-industrial societies to export food was seriously limited. Only the most fertile areas would have had significant excess food to export. And only for the most efficient food sources, mostly only some cereals and potato had yields high enough to create exportable levels of food. Additionally in pre-industrial era seas had much more fish, allowing fish to be exportable source of protein.

Another large difference the level of technology makes is that before industrialization high levels of agricultural production were not sustainable. Soil quality would be continuously dropping due to intensive agriculture and irrigation. Chopping the timber and wood required for the ships and other infrastructure would cause deforestation and severe erosion. The fragile balance of production of consumption would have been vulnerable to disturbances caused by epidemics, which would quickly spread along busy trade routes to the densely populated cities.

So the real limiting factors would have been access to rich agricultural areas with surplus food production and the time you have before your natural resources become depleted. In addition, there are issues with economic balance that should be considered in scenarios where an area imports large portion of its food. That food needs to be paid somehow, even if its just not having taxes to spend on something else.

  • $\begingroup$ I would think there would have been mining colonies that were 100% imported food. $\endgroup$ Jul 31, 2015 at 23:11

The question is based on a misconception:

I'm making the assumption that importing food comes with some risks. The weather can be unpredictable, it is risky also because of war. More broadly, it makes you more vulnerable to others if you depend on imported food. It's still a problem today with food but with other resources as well.

For a small or medium-sized country relying on domestically-grown food exclusively is more risky than relying on a healthy mixture of local and imported food. The reason is the lack of diversification.

Local weather can be unpredictable; there can be a drought covering most of a small or medium-sized country. Local animals can succumb to a contagious disease. One province can fall into civil unrest.

But for the entire world (or at least for an economy-world in the sense of Fernard Braudel) this is much less likely. A country can import food from wherever it is available; if no food is available in the entire economy-world then it means that the civilization is at an end anyway...

A large country, such as modern U.S.A. or the ancient Roman Empire is an economy-world in itself; such a large country may choose to forego imported food, because it is large enough to find sufficient diversification domestically.

Basically, putting all your eggs in one basket is risky. Sourcing your eggs from all over the world is much safer.

But what about pre-modern?

For a pre-modern country (meaning a country which does not yet have efficient overland transportation) the fundamental limitation is that before the advent of pervasive canal and rail networks transporting food overland was prohibitively expensive and, really, impossible for large quantities. Most food had to be grown locally, simply because there was no way to carry it overland.

In the ancient world, cities such as Rome (with its own dedicated port at Ostia) or Constantinople could rely on imported food brought by ships. But an inland city such as Cologne or Turin had to source their food from nearby farms.


It depends on your definition of "pre-modern".

  • Romans importing food from Egypt was during 'Pax Romana' where advanced trading routes connected all parts of the Roman Empire. Free people were better fed than slaves. All that fell apart at Dark Ages.
  • During Dark Ages most people lived in their village, never left, and consumed food they themselves grown in close area. Only addition to local diet would be salt and few (expensive) spices. Nobility lived better, but was minority.

pre-modern is big place.

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    $\begingroup$ Um but the dark age was only in Europe and it's not related to the tech level. $\endgroup$
    – Vincent
    Dec 17, 2014 at 21:30
  • $\begingroup$ Of course - but question is: "Is dark Ages pre-modern or not", according to you. Can you link to some definition of pre-modern? $\endgroup$ Dec 17, 2014 at 21:34
  • $\begingroup$ the 2 characteristic mentioned are : no steam boats and no refrigeration (although it's not specifically mentioned). Pre modern is not really clear because the concept of modernity came gradually starting at the renaissance according to Wikipedia and History SE. Thus we could say more or less that everything before 1600-1700 is pre-modern. Does that make sense ? $\endgroup$
    – Vincent
    Dec 17, 2014 at 21:40
  • $\begingroup$ I can change it to pre industrial $\endgroup$
    – Vincent
    Dec 17, 2014 at 21:41
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    $\begingroup$ "before 1600" still includes both Pax Romana era and Dark Ages - so it's not much of an improvement. $\endgroup$ Dec 17, 2014 at 21:46

If you want to have a state which relies exclusievely/mostly on import for food, you have to consider how that state came to exist at all. Let's review a few points that are worth considering.


You have to consider how come a state that is strongly dependent on trade for basic resources like food came into existence and, maybe more importantly, kept independent, at least to the point of the story. Different reasons can be seen to explain that. In particular,

  • it is a vassal country. It is independent in name only. In reality, it could be seen as an autonomous state within a larger one. The city-states of the Holy Roman Empire could be a good illustration.
  • it is a new country. A gold mine was discovered and the first inhabitants are fully dedicated to the new trade and have basically no time for farming. Furthermore, the commerce flourishes and they can import a sizeable portion of the consumed food. But as the time grows, farming around the mines will be done to feed the population and increase the benefits.
  • it is a trade hub. It is very well situated on the roads of the international exchange of goods, and as the business got strong, they can actually buy the products transiting through it. I'll come back to those later.


Unless the state is limited to a city (and even then), some ways of producing food always existed. Consider the following cases.

  • It's a small island? For sure there are some fishes around.
  • It's in the middle of the mountains? Goats, sheeps, or cows could graze on the mountains sides.
  • It's in the middle of a large desert, then the Oasis will allow to get some fruits, vegetables, and feed a few goats for the milk and some meat. Or you might travel around with small herds to get to the best grass plains (Mongolia).

Without any other factors, those lands would harbor only a few people living there. Import is expensive, and you need to pay for it. How, if you have only few resources.

And you also need a reason to import: your population is larger than what the land can sustain.

So generally, you never get to 100% imported food, for the simple reason that you can always produce something locally. And it is cheaper.


Consider a state which has some small resources. Then, for some historical, economic, political reasons the population start to grow. The state develop strongly its trade capacities. People get richer, and more people migrate to it, and those living there have more healthy children. Slowly the food resources of the country would not suffice for the increasing population. As trade is a major point of the (now, relatively rich) state, they import it. Anyway a lot of food already transit through the state, it is pretty simple to actually buy it.

As some other pointed out, the problem is that to be able to import, you need that other countries are willing to export. That either mean, very expensive or that the other countries have a surplus. Salted-Meat could be transported of ships for some months (think about transatlantic trade, or whaling), but the population of the 17th Century had often a meat-free diet.

the poor [...] subsisted on food like bread, cheese and onions. Ordinary people also ate pottage each day. This was a kind of stew. It was made by boiling grain in water to make a kind of porridge. You added vegetables and (if you could afford it) pieces of meat or fish.

-- [Source]

As other answers state it, the grains could travel for quite some time, to make it a reasonable imported good.

Illustrating examples

History provides a few examples of trade centers with a high importation system. In a few minutes search on the web, I couldn't find any precise values, but you might consider the following illustrations

  • Venice. It was already mentioned in another answer, but Venice started relatively small and grew to be a major trade centre. It is worth noting that in the 6th Century,

    Fishing is the means of livelihood, salt the industry

    -- [source]

    As they became richer, Venice acquired more land. So probably the net import from other countries wasn't so high. But imports from mainland, or Dalmatian territories was probably high to feed the 170,000 inhabitants of Venice.

  • Kingdom of Jerusalem. Was a Kingdom built by the conquest from the Crusades. It was established in the 11th Century and ruled by Europeans. The agriculture of the land was quite limited, and they relied heavily on imports. It was a very important trade cross-road, but they nevertheless depended on financial support from Europe. As a consequence,

    the kingdom was not wealthy, depending on trade with the Muslims, banking activities, and taxes on pilgrims to keep the government operating and to provide for defense. Though there were some fertile districts, much was barren, and in bad years grain had to be imported from Syria to feed the Christians.

    -- [source]

    Which probably explain why it was relatively short-lived.

  • First colonies on the American Continent. They were not self-sufficient, and the imports were very hazardous (time and risks). That explains why the first colonies, and in particular in North America were struggling. When they develop their self-subsistance, they fared progressively better.


I am not very original, but I would conclude like most of the others. It would be hard to quantify the amount of food import that a country might tolerate. But I hope I managed to give you an idea of the several factors you would need to consider when building your state. And on the top of the transportation risk, you add political risk of dependence. And that is often avoided (if possible) by any state.


For staples you don't want to import any of your food because of the risks you mentioned, for luxuries it depends on how much you produce and how much you're willing to spend to get more. If you produce no luxury foods then obviously 100% of your luxuries are imported even if that is zero pounds of food per year and your whole country survives on staple grains etc...

If you have the national treasury for it and you don't produce any food at home then anything up to and including 100% of your country's calorific needs can be supplied by foreign trade, it has happened in living memory, several African states have in the past few decades grown exclusively cash crops for a season or two while under pressure to repay international loans and bought in their daily bread but it's not a good position to be in, especially when your cash crops fail.

Edit: I should add that that is if you have neighbours willing to trade, otherwise you have no show, and of course if they do trade and then their harvests are bad and you're reliant on them then you're in a lot of trouble.


Some detailed information about Rome's grain imports:


I understand a full 33% came from Egypt during the early Empire.



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