How Ancient Cities Shaped Modern Urban Development

Once upon a time I almost called this YouTube channel some variation of Urbis Historia. That was for a reason. The history of the city and the history of human civilization are spiritually and definitionally linked. As cities change, everything about human society must change with them. This makes cities the apex of human achievement, they are the greatest things that humans ever invented. And because of this, the consequences of the mismanagement of cities can be catastrophic. But before the invention of cities, the apex of human achievement was the village.

Beginning in the Neolithic period, or the late Stone Age, humans began to shift away from a nomadic hunter-gatherer lifestyle and towards a lifestyle centred around seasonal and then permanent villages that were "fixed" geographically. "Fixed" is really the key word here. Archeologists have determined that once these villages reached a sustainable size, they stopped growing, and could persist unchanging for potentially thousands of years. In practice, these unchanging villages settled at no fewer than 12 families and no more than 60. This remarkable stability meant that Neolithic villages had millennia to mature, and as they matured they generally settled on the same design.

Even more remarkable is the fact that the physical design of Neolithic villages tended to naturally produce the same type of government. A council of elders which ruled by consensus. Villages were just like that for thousands of years. But then, in the late Neolithic period, a series of major technological breakthroughs suddenly increased crop yields tenfold. Now, for the first time ever, these tiny sustainable villages were flooded with massive food surpluses. The generations living through this transformational era quite suddenly became the wealthiest people who had ever lived.

But the wealth created an entirely new and unforeseen class of problems. The food surplus caused an immediate population boom, and before you knew it, the first cities were born. The archeological record for these first cities tells us something really counterintuitive. Despite the tenfold increase in food production, the people who lived in the new cities actually had a worse diet than the people who lived in the old Neolithic villages. More food, but a worse diet. Huh?

There are two reasons for this. First, the explosion in food production was largely limited to three to five crops. So there was more food to go around, but the food that most people got to eat was basically bread and porridge, it wasn't nutritious at all. Second, to the extent that there was nutritious food, it went to a growing class of non-agricultural workers. As population boom continued, we find archeological evidence of all sorts of new diseases popping up in the cities. A combination of worse nutritional standards and a rush of new diseases meant that when

humans moved from the villages to the cities, life expectancy fell by about 5 years. People had never been richer, but an inability to fairly distribute that wealth meant that workers were eating worse, living worse, and dying younger. Warfare had existed since the first Neolithic villages, but the scope of it was mostly restricted to the theft of livestock and, uh, women. Sorry for putting it that way, but it's true. Warfare fundamentally changed with the first cities. The technological boom and the specialized non-agricultural workers produced an unprecedented amount of material wealth. Copper metalworking, complex clothing, specialized pottery,

all of this was done with brand new technology, which made these new cities unimaginably rich. But the wealth brought with it danger. Rival cities now had more to gain than just livestock and women. Sorry. Immediately after the invention of cities, we see walls going up around the cities. The professionalization of warfare had begun. Speaking of warfare, the dizzying level of wealth meant that the consensus-based governing structures from the old Neolithic villages had to go.

The first cities were ruled by a new class of kings and priests. Under this new system, society fundamentally changed. Power and wealth were brutally and sometimes violently centralized under the kings and priests. Workers in the new cities were somehow less free than they had been in the old villages. After a while, that lack of freedom became central to propping up these urban economies. Limited forms of slavery had existed back in the old Neolithic villages, but with the cities, slavery became institutionalized. In Mesopotamia, we know that at least 5% of the population of cities were

slaves, and as these cities became more and more wealthy, the number of slaves tended to increase. The important takeaway from this is that all of this new wealth did not really help workers. Cities unlocked an unlimited amount of material wealth, and because of an inability to distribute that wealth, people had no choice but to work harder and die younger. What a tragedy. And yet despite these initial setbacks,

the city continued to evolve as it moved into Europe through Greece. The agricultural land in Bronze Age Greece was relatively poor compared to Mesopotamia, which reduced the amount of material wealth floating around these new cities. Over time, this reduced the power of the kings and the ruling class of priests, making these new cities a lot less hierarchical than their Mesopotamian cousins. Tough geography meant that these new cities had to grow up in a dangerous neighbourhood. As a response, they developed robust political systems that were able to mobilize the entire

city when under threat. The old Mesopotamian cities evolved to be top down and fragile, while the new Greek cities evolved to be bottom up and resilient. By the 5th century BCE, Greece's complex political institutions meant that Greek cities could field armies 2-3x larger than similarly sized Mesopotamian cities. As the Greek cities began to mature, so too did their thinking about what cities aught to be.

Greece still had many villages that were modeled on the old Neolithic villages from back in the day. These villages were still governed by councils of elders that ruled by consensus. The Greeks struggled to understand what separated these old consensus-based villages from the new dynamic cities with their complex political institutions. They knew that they were different, but they wanted to understand why they were different.

They said that if an urban centre was too small, like the old villages, then they would lose their autonomy and fall into the political orbit of a larger city. If they were too large, then they would lose their unique character and their shared political purpose, and fracture. Where does one draw this line? Aristotle says that the ideal city should be large enough to be self sufficient, but small enough for a person to easily see the whole city at once. Large enough to be political independent, but small enough to walk across. Aristotle

didn't know it at the time, but he had just stumbled upon a Universal Human Constant. In the late 1970s, an engineer working for the US Department of Transportation named Yacov Zahavi made a remarkable discovery. He found that across cultures, people will happily commute for about 1 hour per day. 30 minutes each way. This may not seem that exciting at first, but his

breakthrough discovery was that this remains true regardless as to the mode of travel. Walking, biking, horseback, rail, car, dirigible, space ship, Zahavi found that people will happily make the trip so long as the travel time is no more than 30 minutes each way. This was a significant breakthrough in the field of urban planning. It meant that one could mathematically predict the natural size of a city simply by figuring out how far one could travel in 30 minutes. 15 years later, an Italian physicist named Cesare Marchetti popularized Zahavi's discovery in his paper "Anthropological Invariants in Travel Behavior," (nerd alert),

and henceforth this principle became known as Marchetti's Constant. Isn't that annoying? In the years since its discovery, Marchetti's Constant has been tested and found to be true not only across every region of the world, but across all of history. Remember what Aristotle said? A city should be small enough for a person to easily see the whole city at once. How far away is the horizon? About 5km. So according to Aristotle, a city should be no larger than 5km from end to end. Or, to think about it another way, a radius of no larger than 2.5km from the centre of the city to the edge.

How long does it take to walk 2.5km? 30 minutes. That's Marchetti's Constant. Aristotle was saying that when people can no longer make most of their trips in 30 minutes or less, cities begin to lose their unique character and their shared political purpose. He knew it 2300 years before Zahavi or Marchetti. I mentioned this briefly years ago in the video "Work," but it's worth repeating here that human brains love 30 minute increments. Across the world, we find that Neolithic humans measured time by tracking how long it took to make a certain tool, or how long it took to cook a certain meal,

or how long it took to grind a certain amount of grain, or how long it took to burn a certain amount of wood, or how long it took to walk a certain distance. All around the world, people considered these things 1 unit of time, and they all worked out to be approximately 30 minutes. We find that the same 30 minute benchmark was important even in the semi-permanent seasonal settlements that predated the first Neolithic villages. Even here,

we have archeological evidence that people built their sleeping area no more than 30 minutes away from where they made their stone tools, which was no more than 30 minutes away from where they stored their food, which was no more than 30 minutes away from their religious shrine. Marchetti's Constant, even among hunter-gatherers. Marchetti's Constant obviously applied to the first Neolithic villages, but it remained true for the first cities. Uruk, considered by many to be the world's first major city,

had a walking radius of almost exactly 30 minutes from the centre of the city to the walls. The Royal City of Ur had a walking radius of no more than 15 or 20 minutes. The city of Babylon had a walking radius of about 12 minutes. The city of Nineveh was similar, about a 12 minutes. The city of Memphis was even smaller, it had a walking radius of only 8 minutes. Fast forward to the Iron Age. At the peak of its power, the Greek city of Athens was a sprawling metropolis and one of the mightiest cities in the world, but even mighty Athens had a walking radius of no more than 18 minutes.

If you're watching this video you probably have at least a passing familiarity with the ancient city of Rome, so I trust I can go into a little more detail here. The Pomerium, which as we all know was the semi-mystical line that showed where the walls of the old city used to be, were at most a 22 minute walk from the centre of the city. What made Rome unique was that the extreme amount of wealth and treasure and slaves flowing into the city allowed for it to grow beyond the Pomerium into a megacity of more

than 1 million inhabitants. This made Rome way too big. Marchetti's Constant sets a maximum walking radius of no more than 30 minutes, but the walking radius of ancient Rome was more like 90 minutes. As a consequence, people rarely left their own neighbourhoods, and these areas became self-sufficient and took on unique characters of their own. Because of its extreme wealth, Rome always struggled to function as a cohesive city. On paper, it violated Marchetti's Constant, but in practice, it was really one central city

within the Pomerium with several self-contained suburban cities glommed onto it. It made no sense, and the people at the time knew that it made no sense. Over the centuries, many elaborate schemes were drawn up to move thousands of people out of Rome and shrink the city down to a more manageable size, but none of these schemes were ever successful. What about the big Medieval cities? Around the year 1400, the largest city in Europe was either Paris or Constantinople. In Paris, it was possible to walk from the centre of the city

to the edge of the city in just 22 minutes. In the case of Constantinople, geography made the city oddly shaped and huge, but even here the urban walking radius never exceeded 30 minutes. Around the year 1450, the largest city in the world was Beijing, with a population 3-4 times larger than that of Paris or Constantinople. Was Beijing's walking radius also 3-4 times larger than Paris or Constantinople? No. Despite its size, Beijing's walking radius never exceeded 30 minutes. Marchetti's Constant was a remarkable natural limit on cities that emerged spontaneously all over the world. It's remained consistent across all of human history. Across all

types of geography, across all levels of wealth, and across all different cultures. That is, until something catastrophic happened to cities in the 1600s. Capitalism. Beginning in the 17th century, there was an explosive increase in overseas trade, which caused a severe concentration of wealth in port cities across Europe. The old Medieval cities had spent centuries evolving into a useful form with a walking radius of no more than 30 minutes. But the massive influx of wealth triggered a sudden

building boom in the port cities and a sudden disinvestment in the old inland Medieval cities. This change was incredibly disruptive to daily life. The old Medieval cities had evolved slowly along topographical lines, meaning that they were all uniquely shaped depending on the hilliness of the area, or the access to fresh water, or the quality of the soil. In other words, they obeyed the laws of nature.

The booming port cities were suddenly so rich that they could afford to ignore the laws of nature. In order to accommodate all of this new wealth, they began blindly building out into the undeveloped land surrounding the cities. But they didn't build in the way that cities had been built in the past. The old Medieval cities had been carefully built up over centuries until they reached a sustainable size. Beginning in the 17th century, the booming port cities were no longer built in that way. Wealthy capitalists bought up huge stretches of empty land and developed it

all at once. They built straight over the hills and the rivers and the rocky soil that had served as natural barriers for the old Medieval cities. What had once been done carefully over centuries was now built recklessly over decades. This explosion of wealth allowed for behaviour that was completely anti-historical, in the sense that people began to ignore the natural physical constraints that were placed upon cities. They also began to ignore the psychological constraints on the human brain. For the first time basically… ever, the capitalist builders began to systematically violate Marchetti's Constant.

This reckless expansion meant that in an ever-increasing number of cities, it became impossible to walk from the centre of the city to the edge of the city in 30 minutes or less. Think carefully about what happened here. The influx of cheap money into the port cities induced a kind of mania. Natural laws of the city like Marchetti's Constant were disregarded in order to build as quickly as possible. Real human preferences were ignored in order to accommodate this fake thing called capital.

Lewis Mumford, a 20th century historian specializing in the history of the modern city, summed this change up in one sentence. "The nature and the purpose of the city had been completely forgotten." Urban growth, or sprawl, is really a creature of capitalism, and as it accelerated through the 17th, 18th, and 19th centuries, a really perverse thing began to happen. Land speculation grew into an industry unto itself, and in some cases became even more profitable than the overseas trade that kicked this whole thing off.

The buying and selling of land on a speculative basis was basically just gambling. It added nothing to society, but whoever happened to be holding the right land at the right time hit the jackpot. All of this speculative churn dramatically drove up the price of land all across Europe. To be clear, these speculators often weren't even building anything, they were just buying and selling and buying and selling and driving the price of land up and up and up. By the 19th century, empty land was 50 to 100 times more expensive than it had been before

the mania began. Land speculators were becoming unimaginably rich without even building anything. A new term was invented for this new class of capitalists who got rich over dubious schemes like land speculation. They called them "millionaires." It was not meant as a compliment. This speculative mania of the 19th century led to some unintended consequences. Back in old Medieval Europe, housing took up about 10% of a working person's income.

Costs were fixed and consistently low. The thing that made Medieval workers lose sleep at night was the price of food, which consumed about 50% of a worker's income. That's why there were riots whenever the price of food spiked. By the 19th century, the unambiguously good news for everybody was that industrialization was beginning to drive down the price of food. This was probably one of the greatest things that has ever happened, each marginal decrease in the price of food instantly increased the standard of living of poor people, it's hard to think of any other innovation that has helped so many people so quickly.

However, while the price of food was beginning to be driven down, rampant land speculation was driving up the cost of housing exponentially. It would seem that this would all be heading for a crash. There is, after all, a physical limit on how much a city can sprawl. But in the 1860s, our old friend the Industrial Revolution intervened, and that physical limit fell away. By this time, passenger rail for the purpose of commuting to work was beginning to go mainstream. If land speculators could influence where the new rail

lines were built, they could hit the jackpot just for owning random bits of land in the middle of nowhere. This kicked off a second golden age of land speculation, and since it all depended upon where the rail lines were built, it created limitless opportunities for corruption. The thing about Marchetti's Constant is that it remains true irrespective of the form of transportation. Human brains will naturally favour a 30 minute walking radius, but they

will also favour a 30 minute radius when traveling by rail. As speed increases, so does distance. This meant that with the railways, cities began to sprawl in every direction at once as fast as people could build. Industrial sprawl in the 19th century created an unconstrained capitalist feeding frenzy. We've never seen anything like it before or since. And what made the

feeding frenzy particularly egregious was that throughout it, very little was done to actually improve the material conditions within existing cities. Through this period, the city was reduced to nothing more than a money-making instrument of the capitalist class. Lewis Mumford vividly described the decline of the city in the 19th century. "In the interest of expansion, capitalism was prepared to destroy the most satisfactory social equilibrium. [.] No matter how venerable these

old uses might be, [.] they would be sacrificed [.] to financial gain." In the 19th century, working class people really got to experience the wonders of the Industrial Revolution first hand. Welcome to Hell! The old Medieval cities were never great and they were rarely even good, but at least they worked. In the 19th century, because of all of this new capitalist churn, European cities stopped working.

Medieval cities were extremely expensive to build, but they always stopped growing before they hit a walking radius of 30 minutes. This meant that once Medieval cities were built, and they could be maintained relatively cheaply for centuries. The Industrial Revolution flipped this equation on its head. The rampant land speculation in the 19th century incentivized cities to sprawl in all directions at once using the cheapest building materials possible.

Nowadays we have a term for these types of neighbourhoods. Slums. The new industrial slums were awful places to live, but they were extremely profitable to the land speculators and the industrialists who built them. The cost of maintaining the old Medieval cores of cities was trivial, but in the end it was less profitable than building brand new slums on empty land, and so over time, capital investment flowed away from the old Medieval cores and into the more profitable industrial slums. The ultimate irony is that these new industrial slums were so poorly built that they had to be

torn down and rebuilt after only 20 years. The old Medieval cities were expensive to build, but they lasted for centuries. The new industrial slums were cheap to build, but they only lasted decades. Over the course of the 19th century, European cities became objectively worse. The material living conditions of workers did not improve at all, and yet industrialists and capitalists became extremely rich. The exponential growth of industrial slums reduced cities to nothing more than a money-making instrument of the capitalist class, and everybody else paid the price for it.

Up to this point in history, most cities had been built alongside rivers. The reasons for this should be obvious. Free drinking water, free sewer system. Two sides of the same coin, so to speak. Obviously one of these should happen downstream of the other, but it took humanity an embarrassingly long time to figure that out. One of the problems with these new industrial slums was that they were being thrown up so quickly that they ignored the natural geography of existing cities.

The new slums either lacked access to fresh water, which meant that they lacked access to a natural sewer system, or they were built on land that was prone to flooding, which meant that at certain times of the year, they became the sewer system. Welcome to Sh*t City! Lewis Mumford described the disgusting living conditions of 19th century slums, "never before in recorded history had such vast masses of people lived in such savagely deteriorated environment, ugly in form, debased in content."

Cholera and typhoid fever became alarmingly common in a way that it never had been before, a single outbreak in a city could easily wipe out 10,000 people. Even the air became poisonous. The new industrial slums and their adjacent factories spent all day burning coal and belching poisonous black soot into the air. The soot got all over people's clothes, into the soil, into the water, into people's homes, and even into their lungs. We now know that prolonged exposure to this soot causes permanent brain damage, and everybody in the industrial slums was exposed.

Researching this video I was surprised to learn that breathing soot damages one's taste buds, which may explain why English cuisine evolved to be, let's say, heavy on texture and light on flavour. Nobody could taste anything! In short, the industrial slums created a hell on earth. The long-term health effects of this prolonged exposure poisonous air and contaminated water was catastrophic, and to examine these effects it might be best to look at 19th century New York City. In 1810, New York City booming and just beginning the process of industrialization.

And since it was the 19th century, we know that the rate of infant mortality was extremely high. 12% of children died before their first birthday. Over the next 40 years industrialization came to New York, and with industrialization came the vast industrial slums that ignored the natural geography of the city. By the year 1850, pollution and poor sanitation had poisoned the air and contaminated the water, which moved infant mortality from extremely high to extremely-extremely high. By 1850, 18% of children died before their first birthday.

By the mid-century, industrialization kicked into overdrive, which meant that the problem was significantly worse only 10 years later. In 1860, 22% of children died before their first birthday. Ten years after that, it was even worse. In 1870, 24% of children died before their first birthday. In only 60 years, New York City had increased its population by 10x, had industrialized its economy, and in doing so had become one of the richest cities in the world. And yet over the same time period, the living conditions of working people was declining, and because of this, infant mortality doubled. New York became rich,

but it had to step over the bodies of tens of thousands of children to get there. Earlier, I called industrialization driving down the price of food probably one of the greatest things that has ever happened. According to some studies, cheap and available food increased life expectancy by 4-5 years. But according to these same studies, out of control pollution simultaneously reduced life expectancy by 4-5 years. The living conditions in the industrial slums were so bad that the immense health benefits of the Agricultural Revolution were completely wiped out.

Working people did not begin to see the benefits of industrialization until well into the 20th century. What am I saying here? I'm saying that cities are the greatest things ever invented by human beings. By almost any metric, people today are unimaginably wealthy when compared to our ancestors, and the thing that has made us wealthy is the city. And yet throughout history, there's this weird paradox. Whenever there's a societal change and a massive amount of new

wealth flows into cities, this creates temporary distortions which tend to cause the standard of living of working people to decline. When we moved from Neolithic villages to the first cities, the kings and the ruling class of priests became unfathomably rich, and yet the people had no choice but to harder and die younger. When cities found their natural size, land speculators reduced cities to nothing more than a money-making instrument of the capitalist class by inducing endless sprawl, enriching themselves in the process and impoverishing everybody else in their wake.

When industrialization showed the promise of eliminating food scarcity once and for all, which to our ancestors would have seemed like an infinite amount of wealth, industrialists instead created endless seas of industrial slums, which led to a steadily declining standard of living. They took infinite wealth and made working people live in their own filth. Obviously people today are better off than people were 100, 1,000, or 10,000 years ago. But the pattern over time is fairly consistent. A wave of capital rushes

into cities, the ruling class gets drunk off of the new wealth, and they begin to behave erratically in a way that you could describe as anti-social or even anti-human. This behaviour can be overcome, the influx of wealth can find its way to workers, but reform is difficult, and it often takes centuries.