The actual Roman Empire was fantastically diverse and more importantly, its military success hinged on its diversity at every stage of its existence. In many games and cultural products, that diversity is obscured because we lose sight of ethnic, religious, linguistic and cultural divisions which were very important at the time, but no longer matter to us very much. Let’s take a snapshot of Roman territory in 218 B.C. to give a sense of this.
Quite a few people look at a map like that, classify most of Rome’s territories as “Italian” and assume there is a large, homogeneous ethnic core there (except, I suspect, anyone who has actually been to Italy and is aware that Italy is hardly homogeneous, even today!). But Roman Italy in 218 B.C. was nothing like that.
Peninsular Italy (which doesn’t include the Po River Valley) contained a bewildering array of cultures and peoples: at least three distinct religious systems (Roman, Etruscan, Greek), half a dozen languages (some completely unrelated to each other) and many clearly distinct cultural and ethnic groups divided into communities with strong local identities and fierce local rivalries (if you want more on this, check out Salmon, The Making of Roman Italy (1982), Fronda, Between Rome and Carthage (2010), and Keaveney, Rome and the Unification of Italy (2005)).
The Roman army was by no means entirely Roman – it was split between Roman citizens and what the Romans called the socii (lit: “allies”) – a polite term for the communities they had subjugated in Italy (a periphery!). Rome demanded military service – this was the resource they would extract – from these communities; the socii pretty much always made up more than half of the army. Diversity was literally the Roman strength, in terms of total military force. Without it, Rome would have remained just one city-state in Italy, and not a particularly important one besides.
(As an aside: while citizenship is extended to nearly all of Italy in the 80s B.C., by then Rome is making extensive use of non-Italian troops in its armies. by the early empire, half of the army – the auxilia – were non-Roman citizens recruited from the provinces. Roman armies were essentially never majority “Roman” in any period, save possibly for the third century. And before anyone asks what about even earlier than my snapshot – it is quite clear – both archaeologically and in the Romans’ own foundation myths – that Rome was a fusion-society, culturally diverse from the city’s foundation. Indeed, sitting at the meeting point of Latin and Etruscan cultural zones as well as upland and coastal geographic zones was one of the great advantages Rome enjoyed in its early history, as near as we can tell.)
Outside of Italy, narrowly construed, the diversity only increases. Sicily’s population included Greeks, Punic (read: Carthaginian) settlers, and the truly native non-Greeks. Sardinia and Corsica had their own local culture as well. Cisalpine Gaul – the Po River Valley – was, as the name implies, mostly Gallic! As the Romans expended into Spain during the Second Punic War, they would add Iberians, Celt-Iberians, and yet more Punic settlers to their empire. And even those descriptions mask tremendous diversity – Iberians and Celt-Iberians were about as diverse among themselves as the Italians were; a quick read of Strabo reveals a wonderful array of sub-groups in all of these regions, with their own customs, languages, and so on.
Even if the Romans didn’t raise military force directly from any one of these groups, they do need to raise revenue from them – remember, the entire point of having the empire is to raise revenue from it, to make other people do the farming and mining and other labor necessary to support your society from the proceeds of their tribute. To keep that revenue flowing – revenue that, as the Roman army professionalized in the late second century B.C., increasingly paid for Roman military activity which held the empire together – you need to be good at managing those groups. Empires that are bad at handling a wide array of different cultures/religions/languages do not long remain empires.
Bret Devereaux, “Collections: Why Are There No Empires in Age of Empires?”, A Collection of Unmitigated Pedantry, 2019-11-22.
