There are many estimates of the population for the
Roman Empire, that range from 45 million to 120 million with 59–76 million as the most accepted range. The population likely peaked just before the
Antonine Plague.
An estimated population of the empire during the reign of Augustus: ''
Beloch's 1886 estimate for the population of the empire during the reign of
Augustus:'' ''Russell's 1958 estimate for the population of the empire in 1 AD:'' The citizen count in the second century B.C. hovered between 250 and 325,000 presumably males over the age of 13. The census of 70/69 B.C. records 910,000 presumably due to the extension of citizenship to the allies after the Social War of 91–88. Still, even if only males this seems like an undercount. For the 1st and 2nd centuries BC, historians have developed two radically different accounts, resting on different interpretations of the figures of 4,036,000 recorded for the census carried out by Augustus in 28 BC, 4,233,000 in 8 BC, and 4,937,000 in 14 AD. and almost 6 million during the reign of Claudius, not all of whom lived in Italy. Does the census record only adult males, all adult citizens or all citizen. Many lived in Spain, Gaul and other parts of the Empire. If 4.063 only represents adult male citizens there were 13 million Romans, if all adults 6.5 million(or some subset of adult male citizens those over age 13 as the census traditionally did not count children until they were formally enrolled as citizens early in puberty), then the population of Italy must have been around 10 million, not including slaves and foreigners, which was a striking, sustained increase despite the Romans' losses in the almost constant wars over the previous two centuries. However losses were not great all the time; and there was an economic boom from 175 BC; and the PO Valley region was spared the social War and civil wars on the Peninsula. The PO Valley may have contributed half the increase in the number of citizens, Latins and Allies from 3.2 million in 225 BC to 4.8 million and 2.3 million in the Valley. Also, the censuses undercounted by at least 10%. Others find the high side of 13 million entirely incredible, and argue that the census must now be counting all citizens, male and female over the age of 13 – in which case the population had declined slightly, something which can readily be attributed to war casualties and to the crisis of the Italian peasantry. The majority of historians favour the latter interpretation as being more demographically plausible, but the issue remains contentious. The low count of 4.063 million *4.5 million with 10% added for the undercount is also contested since it includes Cisalpine inhabitants except for some tribes who were not yet citizens. The number of Po valley is not known, but if the Romans, Latins and Allies numbered 3.2 million and the Cispalines 1 million in 225 BC it means only 300k increase in 200 years which is highly implausible. Estimates for the population of mainland Italia, including Gallia Cisalpina, at the beginning of the 1st Century AD range from 6,000,000 according to
Beloch in 1886, 6,830,000 according to Russell in 1958, less than 10,000,000 according to Hin in 2007, and 14,000,000 according to Lo Cascio in 2009. Evidence for the population of Rome itself or of the other cities of Roman Italy is equally scarce. For the capital, estimates have been based on the number of houses listed in 4th-century AD guidebooks, on the size of the built-up area, and on the volume of the water supply, all of which are problematic; the best guess is based on the number of recipients of the grain dole under Augustus, 200,000, implying a population of around 800,000–1,200,000. Italy had numerous urban centres – over 400 are listed by
Pliny the Elder – but the majority were small, with populations of just a few thousand. As much as 40% of the population might have lived in towns (25% if the city of Rome is excluded), on the face of it an astonishingly high level of urbanisation for a pre-industrial society. However, studies of later periods would not count the smallest centres as 'urban'; if only cities of 10,000+ are counted, Italy's level of urbanisation was a more realistic (but still impressive) 25% (11% excluding Rome). ==See also==