What's the biggest medieval city I can make?

Question

What's the biggest medieval city, in terms of population, that we can feasibly make? That is, take all factors that affect population, and tilt them all in favour of a large population, without exceeding the technological constraints of the middle ages. Somewhat similar to this question, but we're going for gangbusters.

For example, we could have a city that is:

• the capital of a big empire; bureaucrats, merchants and anybody who's anybody wants to be here
• in the heartland of said empire, safe from war
• situated on major global trade routes, so the population includes substantial foreign-born or temporary residents, as well as businesses and industries related to such trade activities
• fed by a large system of rivers, canals and/or seas that import food to feed the massive population
• the hub of many high-value industries that are labour-intensive but do not require substantial land, say textiles or pottery

The largest medieval cities in real life shared many of these features, and reached up to 1 million inhabitants. Impressively, Rome had this many inhabitants but 1000 years earlier.

Could we do better than real life cities like Chang'an or Baghdad? What were the factors limiting the sizes of these cities, and could they be realistically overcome? Or if we look at this as an alternate history exercise, how large could Rome have become if the empire never collapsed, or alternately Hangzhou if the Mongols never took over?

Answer 1

So actually the largest limiting factor for big cities prior to industrialization (and even then) is illness. Most of the large cities of the past were cesspools where people would move to from elsewhere in search of their fortune, many would die from illness, and some would manage to move back to the countryside to retire. Very much the case with Rome, London, Baghdad, even when they had good sanitation.

With aqueducts and sewage disposal to limit cholera outbreaks about 1 million people is still the maximum that can be handled given the knowledge and sanitation that was available. If you could get everyone to boil their water and drink something that promoted health such as, I don't know, tea, as happened with both China and England then the population can rise to something above a million.

Rome reached the size that it did because that was what could be handled both in terms of people dying from the city itself vs. those moving to the city and the surplus food that the countryside could produce and ship to Rome (after passing through Alexandria (of equal size to Rome roughly)).

Which points to two other problems limiting city size: food production and infant/childhood mortality rates in the countryside that supply the city with population; I don't have good suggestions about the childhood mortality rates.

Rome actually had quite a lot that they could have done with the first problem, assuming making wealthy people upset was an acceptable side effect of producing more grain; there were a few people that actually attempted reforms on that front and things ended badly for them, this should be surprising to exactly no one. That though does point to something that even (or perhaps especially) in medieval times would have to be dealt with for all transportation methods and all grains there is a radius at which that grain can be grown and shipped to the city as usable food. Outside of that radius, it has to be turned into alcohol to reach market basically. To have the the largest city possible you want to figure out that radius, drain all the swamps and convert everything possible to farming food. The problem there is that likely the city already exists and quite likely there are going to be rich people who have estates and farms producing luxury food products that are not going to be pleased with your plan, and being rich, have the ability to do something about that.

Of course, another option is to change what type of transportation that is being used. The cheapest thing is to improve the road system, that will let wagons carry more and go quicker. The best thing is building a canal system. That is actually what China had.

Answer 2

Wrote a little novel by accident, hope it's some kind of helpful.

Answering your question, I will follow these steps:

1. Which cities have been the largest between 1000-1500 a.D.
2. How have they become so large?
3. What have been their main problems which impeded further grow?

The largest medieval cities per population.

1.) Baghdad

Baghdad is often declared as one of or even "the" largest medieval city in the world. Between 900 and 1400 the population often raised and dropped between 150.000 and (according to some sources) 1.200.000 citizens.

1.000.000: George Modelski, World Cities: –3000 to 2000, Washington DC: FAROS 2000, 2003. ISBN 0-9676230-1-4

150.000: Tertius Chandler. Four Thousand Years of Urban Growth: An Historical Census (1987), St. David's University Press (etext.org). ISBN 0-88946-207-0.

1.200.000: http://en.wikipedia.org/wiki/Historical_urban_community_sizes#cite_note-Chandler-79

2.) Hangzhou

Compared with Baghdad, Hangzhou steals the show. According to the Encyclopedia Britannica, Hangzhou had a population of over 2 Million people in the year 1276. This number is a rough estimate and not proven. Local authorities numbered 186.330 families ( with 5-10 people per family ). Thing here is, that they probably failed to count non-residents and soldiers living in the city too. Only registered citizens were counted. However, Hangzhou was surely the largest city of its time with 1-2 Million people.

"Largest Cities Through History". Geography.about.com. 2011-03-02. Retrieved 2011-03-16.

Janet L. Abu-Lughod, Before European Hegemony: The World System A.D. 1250-1350, "All the Silks of China" (Oxford University Press US) 1991, p. 337

How have they become so large?

Baghdad

Baghdad has an excellent location. Controlling strategic and trading routes at the Tigris, as well as superior water supply. Looking at a map from ~900 a.D., water is not an issue at this location. Baghdad was built in just 4 years by roughly 100.000 people from all over the (known) world (Europe, Africa, Asia), with such an effort and budget, that it soon got the reference to the Qur'an's paradise. The fast growing young religion Islam supported the city's growth, as people want to get their place in any kind of paradise.

Due to this role in the Islamic world, Baghdad had to handle massive immigration and this grew fast. Soon it had evolved to one of the largest centers of trading, religion and knowledge. Baghdad was what Rome had been 1000 years ago, just more modern.

Hangzhou Is another piece of paper. Founded in 328 b.C., it grew slowly but steadily. While Baghdad was planned with a massive wall, Hangzhou got it's city wall 900 years in existence. At this time, it started to grow more rapidly. The grand canal was built from Bejjing to Hangzhou which established Hangzhou's critical role in Chinese trading culture. In the 10th century, Hangzhou had an explosion of culture, after it became the capital of the Wuyue Kingdom.

But the REAL flush of population began in the first years of 13th century, when mongols conquered large parts of china. Millions of refugees were searching for safe places and Hangzhou, with his massive walls, seemed capable for many people. In 1275, several decades after the first mongol attacks, the population had been ca 1.750.000 people. In 1276, when the mongols conquered the city, the population dropped immediately.

Monica Cable (1996), "Hangzhou", in Schellinger and Salkin, International Dictionary of Historic Places: Asia and Oceania, Routledge, ISBN 9781884964046

What have been their main problems which impeded further growth?

You might accept an excessive answer, but there's none. Sure, both cities struggled with the same problems as any other megacity of this time, but the real issue was war/politics. 1276, Mongols conquered the Chinese megacity. The story of successful growth has gone in another row after they left. Today, Hangzhou is one of the largest cities in the world, with ~21Mio people 2011, according to the Chinese census.

Baghdad on the other hand, struggled with the raising Caliphates power. 1058 it had been conquered by the Turkish general Abu'l-Ḥārith Arslān al-Basasiri and since then, it seems like Baghdad has become a playball for every warlord in this area.

Answer 3

The strongest limiting factor is food.

There is no way whatsoever to have a city harboring more people than can be fed by the surrounding countryside.

Since your food supply will have to travel by barge and oxcart mostly, and neither modern agriculture nor means of food preservation (like cooling, for example) is available, i doubt you could greatly exceed that which was actually achieved, because the food would have to travel too far. (You need to expand the countryside that feeds your city, resulting in longer routes. You also need to feed the oxen and the barge crews, etc).

Answer 4

Many many things to consider here...

Location will be crucial. There are reasons why large cities only showed up in certain places around the globe prior to industrialization. Location plays an even larger role in the case of a city that is not part of an empire...though I would argue that to be this large in the middle ages you simply have to be a part of an empire, its the only social structure of the era that could support that population for an significant period of time.

• Access to water, preferably a sea or ocean with the addition of access to inland rivers. River deltas supported civilization early on for a reason.
• Access to arable land, you need food after all, you can't import everything.
• Not too cold not too hot. latitude/elevation are important. Its much easier to take care of a million people that don't constantly need fuel for heat. How could you have fed Rome if it were far enough north that the sea froze?
• Centrally located in relation to population density. To be big you have to attract people from all directions.

Question: How big can we get?

Answer: Well I would have to say the answer to that is...about as big as things actually got.

Looking at historic scenarios with modern knowledge is tricky. We know things (even untrained, just from basic education) that could have made cities much larger:

• Basic hygiene
• Modern organization management
• Transportation and storage knowledge
• Literacy

Not having these things leads to problems. For hygiene the obvious problem becomes disease. Disease is still a limiting factor today (less so in the first world perhaps). Medieval medicine could not cope with an epidemic beyond isolating the infected parties.

Organizational inefficiency. The Romans, particularly early on, were crazy well organized and it served them very very well...that sort of trailed off but I am not sure whether that was a cause or symptom of the decline of Rome. When organizations get to the empire size, particularly in medieval times things will be disorganized and efficiency and responsiveness to problems suffer drastically.

No refrigeration, no long distance food shipments...at least not on the scale you would need to get much larger.

Literacy...this sorta goes with organizational efficiency. Literacy makes people more efficient, it improves the flow of information drastically. And accurate information is priceless when trying to manage a large group/organization/empire.

Answer 5

I think the main problem would be to attract people. Past a certain point, the grow of the city would stagnate. You have food but people need to do something as a living. There is possibly a few farmers in the city but most people are either: bureaucrats, soldiers, aristocrats/politician, artisans, merchants, member of the clergy. Most would fall into one of these categories.

Why is it a big city in the first place? Mostly because city will trade with far away merchants, other cities from the Empire and locally. Large cities attract merchant because it's a large market with many opportunities. Large cities might attract artisan seeking work, but these artisans need to sell their product to someone and that is where it gets problematic. The local market become saturated very quickly, so you want to export the goods but other cities are also producing stuff and there is a limit to what they can import. The capacity for exportation is limited by the reach of the merchants. Example: It's good for a coastal city like London to be able to trade with other European cities but it's even better if they can reach the markets of Asia or develop trading companies in America. This opens up a lot of opportunities.

The other problem facing a city like London is that foreign markets already produce goods, they won't buy everything we produce unless we could:

1. specialize our economy. Either to produce something the others can't produce or we should try to focus on something in order to increase the profitability of a specific industry by putting our best resources. This is a summary of David Ricardo's idea on economic specialization. It says that buy investing the best resource in one industry, we can use the best workers, best land, equipment and so forth. We will develop more efficient tools and techniques and we will gain a competitive advantage over the others that could allow us to sell at a better price or increase of profit margin.
2. You can conquer oversea markets and force them to buy your products. One way to do this would be to abolish trade tariff with them but increase taxes on importations. This makes importations too costly and almost force them to buy from you. This will impoverish the foreigners but will increase your sales potential, allowing for more artisan to work in the city.

Answer 6

All major medieval cities are port cities on trade routes. The best, like London and Paris, are at the tops of estuaries, protected from storms and pirates, often originating as a fording place.

Inland cities on caravan routes don't have as much growth potential.

Food does not come just from the immediate countryside. Being on water trade routes means titanic amounts can be shipped of grain, dried beans, salt fish in barrels, corned meat, salt meat, &c.

The limits of cities may include...

Defensible walls. You build walls. People who can't get in cluster right outside in fauborgs. Eventually, you enclose them in the new city walls. At what point are the walls too stretched or the fauborgs an indefensible shape? Give up walls early like London did and you don't have to worry.

Potable water. Barely potable. Even with a major river coming through and little feeder streams, they are often open sewers. I would say 90% of your problem will be solved by aggressive city water and sanitation measures such as no one could be annoyed with in actual history.

Human and industrial waste. Because it affects water supply and spread of disease. Raw human & animal waste being stored until the "honey wagons" come for it is just as bad as the outhouses and latrines and skips and manure piles. Then it gets carried barely outside of town and spread on the fields, and the flies happily swarm it, then fly back to town, and land on your lunch. Black death was a major plague, but there was constant attrition of typhoid, typhus, cholera, and the other lesser plagues brought on by flies and dung. The wastewater from tanneries and abbatoirs fouls the river.

Fire. Lack of piped water means most districts have little hope once a blaze starts. The lack of public firefighters was a major problem, too. This requires another increase in city services.

There may be unknown factors, like only x% of the population can stand city life, so the city will increase only as overall population does. But pretty much everyone needs a chance at work, or they turn to begging and stealing to live. Some, of course, prefer a life of crime, and cities provide anonymity and plenty of victims!

Answer 7

While all other answers consider the problems with food and self sustainability, I will focus on the actual problem of all governments, People. If your city is large there will be more people, which means more crime, which in turn means more government influence. You might ask, why does more people mean more crime? That's because people are greedy, wild, panicy animals. With more government influence comes more rules and stricter laws. This makes people unhappy, get enough unhappy people and you get rebellions and riots. To solve this you need to give your peasants power(unless you are going for a military dictatorship). If you give your peasants power then they are no longer peasants and it is no longer a true medieval city. To solve this(and still have a large city) you have two options. One, you can create an atmosphere of fear, so that the peasants are too afraid to revolt, you can do this using public torture, executions and having little mercy. Two, you can not become stricter, simply taking care of the law breakers as they appear silently and without others noticing.