Introduction
Over the past decades, there has been substantial research on the economy of the GraecoRoman world during Classical Antiquity (Ian Morris. The Measure of Civilization: How Social Development Decides the Fate of Nations. Princeton University Press, Princeton, New Jersey, United States, 2013. 2).
Point estimates for the urbanization rates of the regions of the Early Roman Empire according to the present study.
Thus, the economic productivity across different regions of the Roman Empire was highly heterogeneous, reflecting the fact that the Early Roman Empire was not a centralized State that imposed a uniform set of institutions over the diverse populations under its rule.5 Historians argue that it was only in Late Antiquity, after the 3rd-century crisis, that the Roman Empire became a territorial state (see Harper [2017] and Hansen [2006b]). This urbanized core was a “network” of Mediterranean city-states that was mainly concentrated around the Aegean Sea up to the late classical period (the 4th century BCE), and this core gradually expanded to include the Italian peninsula as well as many lands bordering the Mediterranean Sea. During Classical Antiquity, mainland Greece and the regions colonized by the Greeks by the 4th century BCE appear to have had a relatively constant rate of urbanization from the 4th century BCE to the first two centuries CE. Over the 3rd and 2nd centuries BCE, the Italian peninsula also developed a high rate of urbanization so that by the Early Roman Empire, the most urbanized regions of the empire had a comparable rate of urbanization as the Greek world of the 4th century BCE. By the 2nd century BCE, the city-state of Rome had become militarily hegemonic over nearly all the other city-states, tribes, and territorial states across the Mediterranean and the Black Sea basins, forming what historians today call the “Roman Empire.” However, these formerly sovereign city-states, tribes, and territorial states maintained their distinct local institutions. For example, the Athenian constitution established by the late 6th century BCE operated with minor changes for nearly 700 years, a period that included centuries of Roman hegemony, until the reforms of the 2nd century CE (Hansen [1998]).
The Classical Greek notion of citizenship, which refers to particular city-states, also continued being practiced during Roman hegemony: for example, the famous Greek author from the 1st century CE, Plutarch, was a citizen of the Greek city of Chaeronea. Therefore, as the Early Roman Empire maintained the institutions of a very diverse set of polities, the degree of economic development across its vast expanse was also highly heterogeneous. The economic institutions and living standards in the polis of Roman Alexandria (which papyrus evidence shows it still had a citizen body voting on popular assemblies in the 1st century CE Rostovtzeff [1941], generations after it was incorporated into the Roman Empire as part of the province of Egypt) were perhaps more similar to other major commercial poleis such as Athens and Rhodes than with the areas of Roman Egypt that were outside of territorial jurisdiction of any poleis. By Late Antiquity (a period chronologically defined from the end of Classical Antiquity up to the Early Middle Ages in the 7th and 8th centuries), after centuries of Roman hegemony and after many institutional reforms of the Roman state, the Roman Empire consolidated as a more centralized territorial state (Harper [2017]), as the institutional autonomy of individual city-states was eroded (Hansen [2006b], Bresson [2015]), the institutions and the degree of economic development became likely much more homogeneous across the regions of the Roman world. This means that broad generalizations regarding the institutions and performance of the “Roman economy” are then perhaps more applicable to the Late Roman Empire rather than to the Early Roman Empire
Estimating urban populations in classical antiquity
Hansen [2006a] provides estimates of the population density in the inhabited areas of Late Classical (4th century BCE) Greek city-states based on samples of (typically) small cities surveyed by archaeologists. Hansen’s methodology is as follows: Hansen estimates that there were typically between 30 to 33 houses per hectare of inhabited area and that the typical household in Late Classical Greece had between 5 and 6 inhabitants; thus, the typical population density of Late Classical Greek cities is estimated to be 150 to 200 inhabitants per hectare of inhabited area. These estimates are consistent with the density of houses found in the small 1st century CE Roman cities of Pompeii and Herculaneum, which had estimated inhabited areas of 60 and 20 hectares, respectively, and estimated populations of 10,000 to 12,000 (Pompeii) and 4,000 (Herculaneum). Hanson and Ortman [2017] state that the available evidence of Roman period cities in other regions of the Roman Empire suggests that population densities in small and medium towns were also similar to cities in Late Classical Greece and Roman Italy; thus, they developed a model of urban population density for Greco-Roman cities. Archeological evidence suggests that the typical size of house footprints found in GrecoRoman archeological sites is surprisingly consistent from the Late Classical period to the Early Roman period: although the dispersion in house sizes appears to have increased from the Classical to the Roman period, the mean stayed relatively constant. Hansen [2006a] states that typically, the ground floor of late-classical Greek houses occupied 175 to 250 square meters, and from a sample of 405 house-floor plans, Morris [2004] gives a median size of 230 square meters for Greek houses dating from the 4th century BCE.
Hanson and Ortman [2017] also estimated that in larger cities with around 100 hectares of inhabited area or more, it was common for population densities to be higher. As there were no cars and other modern means of transportation, most people were constrained to walking distances, and so to minimize the distance traveled, cities tended to grow across three dimensions: Hanson and Ortman [2017] estimate that the population density tended to increase in proportion to the log size of the city-area, which implies that population densities could be much higher than 150 to 200 inhabitants per hectare in large cities. For example, consider the Roman city of Ostia, which was built as Rome’s port city and whose population mostly resided in apartments. In the neighborhoods of Ostia surveyed by archaeologists, the density of houses and residential apartments per hectare was between 70 and 90 (depending on how archaeologists interpret the function of architectural units of excavated buildings), which is a density nearly three times higher than in typical (small) Greek and Roman cities, which suggests a population density of 350 to 540 inhabitants per hectare (given household size of 5 to 6). Hanson and Ortman [2017] method suggests that densities for very large cities like Rome and Alexandria were 400 to 500 inhabitants per inhabited hectare.
We define the urbanization rate to be the proportion of the population living in cities with more than 5,000 inhabitants. Note that this threshold of 5,000 inhabitants excludes several famous ancient “urban” sites like the Roman-period town of Herculaneum (estimated population of 4,000) and the Hellenistic-period town of Priene (estimated to have had 500 houses and therefore 2,500 to 3,000 inhabitants). In fact, as we will see, according to our estimate, over three-quarters of the Greek city-states in the 4th century BCE had fewer than 5,000 inhabitants residing in their urban centers. Larger cities like Athens, Carthage, Rome, Alexandria, and Syracuse, with populations approaching or surpassing 100,000, were exceptionally large in Classical Antiquity.
Urban population in the Late Classical Hellenic World
By the late 4th century BCE, most Greek city-states had defensive walls: Hansen [2006a] states that 869 out of 1,035 poleis included in the Polis Centre’s inventory have been precisely geographically located, and of these, Hansen [2006a] states that the central settlements of 438 poleis are explicitly attested as walled settlements by the physical remains of their walls being identified by archaeologists. From these 438 poleis, there are sufficient remains for archaeologists to estimate the area enclosed by the walls in 232 cities. Ober classified the ancient Greek city-states into seven territorial categories: size 1 were very small poleis with less than 25 square kilometers, size 2 had between 25 and 100 square kilometers, size 3 had 100 to 200 square kilometers, size 4 had 200 to 500 square kilometers, size 5 had 500 to 1,000 square kilometers, size 6 had 1,000 to 2,000 and size 7 were the largest with over 2,000 kilometers. He also provides an estimate of the distribution of a hypothetical number of 1,100 city-states by size based on the 672 cases with an available estimate for territorial area.
This study assumes that there were 1,000 Greek city-states by the late 4th century BCE. This assumption is made considering, first, that the 1,035 explicitly attested poleis dated from before 330 BCE in the Polis inventory are a lower bound for the total number of citystates that existed during the Archaic and Classical periods (776 BCE to 330 BCE). Second, not all these cities existed by the late 4th century BCE, as some of those cities, such as Sybaris and Selinous, were recorded as having been abandoned by the late 4th century BCE.
Here’s the table:
Using the estimates from Hansen [2006a] regarding the proportion of the population residing in the central walled settlement of each polis compared to the hinterland implies that the total population of the city-states of the Late Classical Greek world was 9.5 million and a rate of urbanization of 32.7%. For comparison, Hansen [2006a] estimated that the total population of the Late Classical Greek world was likely between 8 to 10 million, which includes several hundred thousand people living in the rural areas of the kingdoms of Macedon and Epirus besides the population residing in poleis. In addition, Ober [2015] produced an estimate of 8.25 million regarding the total population of all poleis and estimated the proportion of the population living in urban settlements with over 5,000 inhabitants at 32%. A rate of urbanization of ca. 32-33% living in towns of over 5,000 inhabitants is very high for a pre-modern society. For comparison, according to Bairoch and Goertz [1986] in 1900, the average rate of urbanization in Europe and North America was 31.3%, in France was 35.4%, and in the United States was 35.9%, at the turn of the 20th century, only Germany, the Netherlands, Belgium, and the United Kingdom had a rate of urbanization higher than 36% of the population living in towns over 5,000 inhabitants. Consider another pre-modern society: Europe in the early 14th century featured an estimated urban population of 5 million (Buringh [2021]) and a total population of ca. 80 million inhabitants (Bairoch [1988]), a rate of urbanization of 6%.
In terms of the number of cities with over 5,000 inhabitants, this study estimates ca. 220 cities in Late Classical Hellas compared to ca. 380 in Europe at the turn of the 14th century; the estimated average size of cities with over 5,000 inhabitants was almost identical as well as the distribution of cities by size (see Table 5), which suggests this estimate is consistent with known distributions of city sizes of more recent pre-modern societies.
Urbanization across the Roman Empire
By the Early Imperial Roman period, Rome had subjected 3.8 million square kilometers of inhabited landmass around the Mediterranean basin and in Western Europe (Scheidel [2007]), a territory that was 20 times larger than the combined territory of the thousand Greek citystates a few centuries earlier. Note this figure excludes the areas often included in maps of the Roman Empire that were not inhabitable, such as the desertic regions of North Africa and the Levant. This inhabited territory also included the territories corresponding to nearly all identified Greek city-states by the late classical period. The present study’s estimate of Roman urban population is based on the survey of cities in the Early Imperial Roman world of Hanson [2017], which identified and geographically located 1,388 Roman urban centers. Among these 1,388 urban centers Hanson [2017] provides estimates of the cities’ geographical areas in 885 cases. These estimates differ in their method: areas enclosed by city walls, inhabited areas surveyed by archeologists, areas covered by urban street grids, etc. In addition, the present study uses data from Karanbinis [2018], who provided estimates of inhabited areas for dozens of Early Roman-era cities in the Peloponnese, Thessaly, Central Greece, and Epirus. As direct estimates of inhabited areas are preferable to indirect.
For example, in late medieval and early modern Europe, there were typically 1.5 to 1.9 times as many cities with between 5,000 and 10,000 inhabitants compared to cities with over 10,000 inhabitants. In Late Classical Hellas, this study estimates that this ratio was 1.69. The distribution of estimated populations for 888 cities of the Roman Empire yields a ratio of only 1.35. In addition, the average size of cities over 5,000 inhabitants is ca. 16,000, which is substantially larger than in Late Classical Hellas (13,300) and higher than the average and at the top of the range observed over the centuries in Medieval and Early-Modern Europe (the average was 14,500 for the five-century average from the 14th to the 18th centuries). The ratio of cities of the number of cities with over 5,000 inhabitants to cities with over 30,000 inhabitants typically tends to be around 11 to 12 (it was 11.1 in Late Classical Hellas and 11.5 for the five-century average from the 14th to the 18th centuries in Europe) but our sample of 888 Roman cities suggests a ratio of only 9.0. Hanson and Ortman [2017] argued that while archeologists are more likely to study the remains of larger cities, it is also more likely the sites of larger cities have been obliterated by modern development. Thus, they conclude that the average size of Roman cities with measured geographical size in Hanson’s dataset should not be expected to be substantially different than the sizes of the cities without measured geographical size among the 1,388 cities in the dataset. But, Hanson and Ortman [2017] also noted it is agreed among specialists that the four largest cities of the empire were likely Rome, Alexandria, Antioch, and Carthage. As these four cities have an estimated area in the dataset, this study estimates the average size of the other 500 cities using the average size of the 884 smaller cities with measured geographical size.
Construction of the estimated urban population of the Roman Empire:
- Regional urban populations
- Smaller on average in Britain, Iberia, and the provinces around the Danube.
- Larger on average in Egypt, North Africa, Syria, the Levant, and Asia Minor.
Roman Italy, Egypt, and Britain as compared to Classical Hellas
A comparison of the estimated urban population of Classical Hellas, Roman Italy, Egypt, and Britain.
All provinces
