These cities were the wonders of the world, seething, stinking, and raucous

From War! What Is It Good For? by Ian Morris. Page 41.

The army was concentrated in frontier provinces, few of which were fertile enough to feed so many men who did not work on the farm (by the first century A.D., about 350,000 of them). The army therefore spent much of its money buying food that had been shipped by merchants from the empire’s more productive Mediterranean provinces to its less productive frontier ones. This generated more profits for the traders, which the government could tax, generating more money to spend on the army, creating more profits still, and so on, in a virtuous circle.

The flows of taxes and trade tied the Mediterranean economy together as never before. Each region could produce whatever it made cheapest and best, selling its goods wherever they fetched high prices. Markets and coinage spread into every nook and cranny of the empire.

Thanks to bigger markets, bigger ships became profitable; thanks to bigger ships, transport costs fell. And as they did, more and more people could afford to flock to the great cities, where the government spent most of the money that did not go to the army. In the first two centuries A.D., a million people lived in Rome—far more than had ever lived in one place before—and Antioch and Alexandria boasted perhaps half as many each.

These cities were the wonders of the world, seething, stinking, and raucous, but full of pomp, ceremony, and gleaming marble — all of which required more people, more food, and more bricks, iron nails, pots, and wine, which meant more taxes, more trade, and more growth.

Little by little, this frenetic activity increased the quantity of goods in circulation. By the best estimates, per capita consumption typically rose about 50 percent in the first two centuries after incorporation into the empire. The process disproportionately favored the already rich, who grew even richer, but every class of objects that archaeologists can count—house sizes, animal bones from feasts, coins, the height of skeletons—suggests that tens of millions of ordinary people profited too (Figure 1.4).

“Who does not now recognize,” the Roman geographer Pliny (most famous for getting himself killed by standing too close to Mount Vesuvius when it erupted) asked “just four years before the battle at the Graupian Mountain, that thanks to the majesty of the Roman Empire, communications have been opened between all parts of the world? Or that standards of living have made great strides? Or that all this is owed to trade, and the common enjoyment of the blessings of peace?” The Roman Empire was no wasteland.