When I lead tours to biblical sites like Ephesus, inevitably people ask, “How many people lived here?” Unfortunately, this question does not have a clear answer because ancient demographics (i.e., the study of populations) is an imprecise field, more art than science. This post introduces and assesses five methods that demographers use to estimate the population of ancient cities: censuses, literary sources, venue sizes, the area of a city, and inscriptions.
Before diving into the demographic methods and numbers, we must address a simple yet bedeviling question: When one is counting the number of people in a “city,” what is the scope of a “city”? In modern usage, city population refers to the number of people living in the built area of the town and excludes those who live in the surrounding countryside. This reflects our cultural understand of city, i.e., a large town, in contrast to the rural countryside. However, in the ancient world, the “city” included both the urban center and the surrounding countryside. The farmland around the city was considered part of the city’s territory, and the people who worked the farmland were members of the city who participated in its economic and social life. When discussing the population of a “city,” we must define the boundaries. This rarely happens, which creates issues. In general, ancient authors include people in the countryside as part of the city, but modern authors count only the urbanized center.
The easiest (and perhaps most logical) way to obtain information about ancient populations is through a Roman census, a government register of the people. Countries today undertake a regular census to measure their populations. This provides accurate data about the number and profile of its people. The Roman Empire, in theory, took a census every five years (cf. Luke 2:1-3; Acts 5:37). However, Roman censuses were not like modern censuses. Their purpose was taxation and military conscription, not counting people. So, women or children—about 75% of the total population—were not registered in the census. The Romans wanted to know who could provide money for their coffers and manpower for their armies, not how many people lived in a city. For this reason, the results reveal more about land ownership than city populations. Moreover, emperors after Titus (79-81 AD) ceased to conduct a census, as the empire was less concerned with taxation and conscription at that point. Of the Roman censuses conducted, only a few returns have survived until today. For these reasons, Roman censuses do not provide sufficient information about ancient populations.
Another common source for population estimates is statements in literary sources. For example, Galen said about his hometown of Pergamon, “[O]ur citizens amount to as many as 40,000, likewise if you added their wives and slaves, you will find yourself admitting that you are richer than 120,000” (On Natural Facilities 5.49). So, the population of Pergamon in the early-second century appears to have been 120,000. However, there are problems with accepting this number uncritically. One, how did Galen calculate 40,000? Was this from a government census, or just his personal estimate? Two, people often discussed the population of their city for purposes of rhetoric or panegyric. They boasted of the size of their city, and so were liable to exaggeration. Three, Galen’s total of 120,000 does not include children. Assuming every family unit had two children, the total population would be 200,000.
In another literary source, Diodorus (17.52.6) says about Alexandria, Egypt, “At the time when we were in Egypt, those who kept the census returns of the population said that its free residents were more than 300,000.” Alexandria was undoubtedly a large city, but there is reason to doubt the precision of Diodorus’ population figure. One, he mentions a census, but his figure is from the government authorities “who kept the census,” not the census itself, so it might have been rounded up. Two, in this section exalting the accomplishments of Alexander the Great, he overstates the importance of Alexandria by falsely claiming, “The number of its inhabitants surpasses other cities.” But Alexandria’s population surely did not exceed Rome’s when Diodorus wrote. Three, later papyrus says the citizens of Alexander numbered 180,000, so we have notable discrepancies in textual sources. Explicit statements are helpful; however, their precision should not assumed, but rather considered with other information. (For more literary references, see Duncan-Jones, The Economy of the Roman Empire, p260, n4.)
A third method for obtaining ancient demographics is the capacity of public spaces, such as theaters and amphitheaters. However, scholars note the size of public venues to establish the relative size and prominence of a city, not to calculate its population. Nevertheless, I mention this potential source because I often hear anecdotally that one can estimate the civic population by multiplying the seating capacity of a theater by 10. Besides the fact that this is not the result of any published research, several problems come to mind. One, there is no way to know the ratio between seating capacity and urban population. Ten is a nice number for a multiple, but why ten and not two or twenty? Two, the size of a theater might be determined by the local wealth of civic rivalries or building customs rather than population. To use a modern analogy, baseball stadiums do not reflect the cities’ population. The Los Angeles Dodgers and Tampa Bay Devil Rays play in similar-sized stadiums, but L.A. and Tampa Bay hardly compare in terms of population. Thus, the size of public venues is not a reliable guide for demography.
A fourth method is based on the physical size of the city. The method is simple—you calculate the area of the city, then extrapolate the population. The larger the city size, the larger its population. To calculate the physical area of a city, demographers look at city walls (because, presumably, people lived within its perimeters), and centuriation (to see what spaces have been divided into the grid pattern for an urban settlement). Population density in pre-industrial urban centers is 150-450 people per hectare (=10,000 m2), and the general average is 200 people per hectare. This average equals 81 people per acre, or 1 person per 50 square meters. So, for example, if a city was a perfect square with 1-km-long walls on each side, it would be 100 hectares, which could fit 20,000 people. If a city was a perfect circle with a 1-km diameter, it would have a size of 78.5 hectares, so it could support 15,700 people. In his article, “The Urban System of Roman Asia Minor,” Hanson proposes this method of demographics as the “least inaccurate available method.” In other words, it’s the best we got! While simple and seemingly obvious, the biggest problem with this theory is that physical remains do not always correspond to settlement patterns. A city wall was not always the boundary line marking where houses were located. This method limits the city to its built-up urban center.
A fifth method for estimating populations is using information from inscriptions. Certain inscriptions catalogue the number of tribes or citizen groups in a city. The total population can be inferred from the number of such civic groups. This method is further discussed in the section below about Ephesus.
The Population of Ancient Ephesus?
As a case study in ancient demographics, let’s consider the city of Ephesus, the capital of Asia during the time of the Roman Empire. Based on different methods, estimates range widely.
Survey data published in 2006 by St. Groh and others (“Neue Forschungen zur Stadtplanung in Ephesos,” ÖJh 75 [2006] esp. 112-13) estimates the population in the 2C AD to be 30,000-70,000 inhabitants. This figure is based on urban size and physical buildings. They explained:
Given the current state of research, information on the population of Ephesus in the 2nd century AD is purely speculative. The size of the urban area, the necropolises, the thermal baths and, above all, the number of urban areas and parcels on these can be used as a basis for considerations. A city area is made up of ten plots, i.e. originally there are ten families with around ten members, a total of 100 people per city area. There are around 300 urban areas in the urban area, of which at least 200-250 or 90-120 hectare are used for residential and commercial purposes, which gives a number of around 25,000 people. This also roughly corresponds to the capacity of the theater (approx. 30,000). If you add other assumed inhabitants in the extended urban area of Ephesus, a population of about 30,000-70,000 people can be expected.
The Roman demographer Hanson provides a similar estimate of 33,600-56,000 people. This is based strictly on the physical area of the city, as defined by the city walls. However, the method seems problematic and the estimate overly conservative. Hellenistic-era walls at Ephesus follow the ridge of Mt. Koressos, but people did not live on the entire slope up to the wall. Moreover, the open plain east of the city outside the Magnesia Gate was settled. The entire area inside the city walls might not have been inhabited, and/or people could have lived outside the city walls. The flaws of this system are most evident, in my opinion, in Hanson’s final estimates. Based on city area, the most populated cities in Asia were Sardis (99,000 people at 250/ha) and Alexandria Troas (69,500 people at 250/ha). While these were important cities, few historians would agree they were larger in population than the coastal metropolises of Ephesus, Smyrna, and Pergamon.
Based on an inscription about the Curetes priests in Ephesus, Knibbe (“The State Market” Research in Ephesos 9.1, 1981) estimates 48 divisions with a thousand free citizens, so 48,000 citizens total. Another inscription (JOAJ 26, 1930, 57ff) about the terms of a gift suggest that Ephesus had at least 40,000 male citizens. If one were to add non-citizens, such as women and children, the total population would be around 200,000 to 250,000.
Conclusion
So, the population of Ephesus can be estimated, based on the method, as being between 30,000 and 250,000 people. The truth probably lies somewhere in between. The wide range indicates the imprecision and limitations of our conjectures. Considering the challenges of ancient demography, we should expect general ranges and relative comparisons, not precise figures.
When people ask me, “How many people lived in Ephesus?”, they are not hoping to hear about the methods and complications of ancient demography. They just want a number. So here’s my short answer to the question—“We don’t know for sure—maybe 100,000-150,000.”
To an open-access journal article surveying in great detail the various methods of historical demography, see Sam Cleymans, "The Shotgun Method 2.0: estimating population numbers for second century A.D. Sagalassos," Ancient Society 48 (2018) pp. 263 - 304