Barbarian migrations are a staple of popular histories of the ancient world. From early wandering groups like the Cimbri and Teutones in the late second century BCE to massive hordes of Goths, Vandals, Juthungi, and the like streaming across the map of the late Roman Empire, it seems that gathering up in huge masses and tromping around the world is just what barbarians do.

But is it? The popular image of migrating barbarian hordes comes from older scholarship, many of whose assumptions and conclusions have been challenged in recent generations. No one today doubts that people in antiquity moved, sometimes in groups, and sometimes long distances, but the idea of massive hordes pouring across the landscape is becoming less and less tenable.

To get an idea of why massive barbarian migrations are questionable, we’ll consider two interrelated issues: numbers and logistics. How large were the groups that moved long distances in antiquity? And how did those groups manage the practical problems that come with moving long distances? This post addresses numbers. In the next post, we’ll talk about logistics. Finally, we’ll see what conclusions we can draw about how and why large groups of people moved around the ancient world.

Ancient sources are notoriously unreliable when it comes to estimating the numbers of people in large groups. Greek and Roman writers trying to describe the movements of large groups of potentially hostile outsiders are especially unreliable. Even today it is difficult to estimate the size of crowds, and we have much better tools at our disposal than ancient authors did. Most writers who report figures for the movement of large groups were not eyewitnesses, and were certainly not in a position to get an accurate count.

Greek and Roman authors had reasons to exaggerate the scale of forces they perceived as hostile intruders. A large movement was more dramatic to write about, and the defeat of a large hostile force reflected more glory on the Greek and Roman armies and leaders who fought them. The literary mood of late antiquity was particularly pessimistic, influenced both by the competition for power among rival generals who needed to claim that they had triumphed over unbeatable odds and the Christian hope for an apocalyptic end of the world. The image of massive hordes of invading barbarians suited the needs of contemporary writers, but that does not mean that barbarians were actually invading in massive hordes. The same dire language was used to describe urban unrest, rural banditry, undisciplined soldiers, even overzealous monks.

Still, there was nothing new about Greek and Roman authors wildly overestimating the size of outside groups on the move. The Greek historian Herodotus in the fifth century BCE famously estimated the size of the Persian king Xerxes’ expeditionary force in Greece (army and navy combined) at a ludicrously high figure of 5,283,220; modern estimates vary, but generally put the total at less than 100,000.

Given these facts, we should be skeptical of ancient sources that breezily conjure up 80,000 Vandals, 150,000 Goths, or 400,000 followers of Radagaisus. While any of these figures could theoretically be correct, and we cannot categorically reject them, none of them is any better than an estimate by an outside observer passed through several hands and recounted by a writer with literary and political axes to grind.

So, how large were the actual groups of people moving around the ancient world? It is impossible to say with any certainty, but we can make a few suggestions. To begin with, the lower literary estimates are a workable upper bound. 80,000 is repeated by enough sources in enough different contexts that it probably represents a literary convention for “a very big number of people.” If we suppose that this literary convention is derived from actual experience of the practicalities of moving large groups of people, then it makes sense to suggest that few if any moving groups in antiquity numbered more than 80,000, and most were much smaller.

Accounts of some late antique battles give figures of approximately 10,000 fighters in the “barbarian” armies. These figures are questionable for all the same reasons described above, but they are not out of proportion to the sizes of known ancient armies. Fighting forces represent only a fraction of an entire population, conventionally estimated at an eighth, or perhaps as much as a quarter in extreme circumstances. A fighting force of 10,000 would then represent a total population of 40,000-80,000. Since the “barbarian” armies in these battles were often temporary alliances of disparate groups, the constituent groups themselves must have been smaller.

Our numbers can only be speculative, but drawing together these inferences, we are probably not terribly far wrong if we imagine most migrating groups in antiquity on the scale of 10,000-20,000 people, with some temporary alliances adding up to 80,000 or so.

In the next post, we’ll think about what it would actually take for even a group of 10,000 or so people in ancient conditions to migrate from one place to another.

Image: Ludovisi sarcophagus, photograph by Jastrow via Wikimedia (currently Museo Nazionale Romano di Palazzo Altemps, Rome; c. 251 CE; marble)

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