Cover photo: A 19th-century steel engraving of the Appian Way. ‘On both sides are tombs and monuments, that of Caecilia Metella in the middle distance. In the foreground the third milestone,’ from ‘A Pictorial History of the World’s Greatest Nations’.

By 338 BC, the Roman state already spanned 8,500 square kilometers, had a population of approximately 800,000, and could field an army of eight legions (four Roman and four allied), totaling 40,000 men, plus a few hundred cavalry (Equites).

Text by Ilias Anagnostakis.

The Roman state up until then was a moderate Italian power of local character. However, the unification of Latium (338 BC) and especially the annexation of Campania (340 BC) were the necessary steps for it to start ‘breaking out.’

Rome itself does not seem to have had more than 60.000 to 100.000 inhabitants (Athens at its peak had 250-300.000¹, while Rome (just the city itself) had about 200.000 in 225 BC), but it had strong growth tendencies. There were scattered settlements and villages in the Latium valley full of “upcoming” Roman citizens. Moreover, Rome generously granted Roman citizenship with the only requirement being military service/contribution, although without the right to vote (Civitas sine suffragio²), which further expanded Rome’s military reservoir. Actual Romans made up 35-45% of any expeditionary force, regardless of its size, with allies comprising the remaining 55-65%, all under Roman command, of course. Polybius indicates that the Romans asked their allies to supply lists of men of military age (απογραφάς των εν ταις ηλικίαις) so that they could ascertain the number of men available for military service.

The deadly Samnite Wars with the numerous and highly warlike Samnites (343-341, 326-304, 298-290 BC), despite some humiliating Roman defeats (Caudine Forks in 321 BC, Lautulae in 315 BC) and heavy losses (over 15,000 men), resulted in nothing other than the further expansion of Rome. This expansion culminated in the battle of Sentinum (295 BC), which was of colossal importance for human history, where 40,000 Romans crushed 45,000 Samnites, Umbrians, Etruscans, and Senonian Gauls, definitively emerging from local obscurity and heading towards dominance over Italy.

And how could it not be so, when Rome was at war every year(!) between 350-241 BC, except for the years 347, 344, 328, 288/7, 285? By the end of the 4th century, Rome expected to expand to 40,000 square kilometers and field 12 legions (60,000 men). By 290 BC, this number would grow to 80,000 men (16 legions). This growth was noted by the Greek King Pyrrhus of Epirus, who, despite winning two battles (Heraclea in 280 BC, Asculum in 279 BC) and a bloody stalemate (Beneventum in 275 BC), during which he annihilated approximately 18,000 Romans and allies, declared that ‘we are fighting a Hydra.’

It was now clear that after the end of the wars with Pyrrhus (272 BC), Rome effectively controlled an area of 80,000 square kilometers through various means and could now field 18 legions (90,000 men), while its population had reached approximately 2.5 million, with Rome itself reaching 150,000.

By 225 BC, Rome had broken all barriers, and according to Polybius³ it could possess 700,000 infantry(!) and 70,000 cavalry (250,000 Roman infantry and 23,000 cavalry, the rest being allies), with a total population now at 4 million.* The statistics reported by Polybius are derived ultimments. The formula togatorum for 225 B.C. listed the required by Rome in that year, and the numbers of Romans mobilized were inscribed in public records.

There, he mentions 49.200 serving Romans and Campanians and 81.600 infantry allies (Etruscans, Umbrians, Sarsinates, Veneti, Cenomani and rest allies), 7.550 cavalrymen (and 57.500 available), while he notes an available number of reserve units of 540.000 men (200.000 Romans). The exceptional British academic and ancient historian Peter Astbury Brunt (23 June 1917 – 5 November 2005) argues that the published Roman census statistics purport to comprise all adult male citizens regardless of age, so a respectable percentage were probably not of military age.

Be that as it may, it is a fact that the Roman human pool was literally inexhaustible. The path to the Punic Wars and world domination was now open…

*This number (700,000 infantry and 70,000 cavalry) was theoretical; obviously, they could not (and there was no reason to) be mobilized en masse. Rome typically mobilized part of these forces, depending on the situation. However, in emergencies (like the Second Punic War), when Rome lost approximately 110.000-150.000 men (dead and captured) in four battles (Ticinus 218 BC, Trebia 218 BC, Lake Trasimene 217 BC, Cannae 216 BC), it had to draw from this enormous pool of men mentioned earlier. Hannibal needed as many victories again to prevail, but he also needed a continuous flow of reinforcements, as his losses were great. With the 4,000 infantry, 200 cavalry, and 6 elephants he received in 16(!) years from the inexplicable clique of merchants in Carthage, he merely labored in vain.

Sources:

Polybius, Histories

Brunt, P. A., “Italian manpower, 225 B.C.-A.D. 14”, publ. Oxford University Press, London, 1971

Matthew J. Mandich, “Urban Scaling and the Growth of Rome”, publ. Theoretical Roman Archaeology Journal, March 2016

Donald Walter Baronowski, “Roman Military Forces in 225 B.C.,” publ. Historia: Zeitschrift für Alte Geschichte, Bd. 42, 1993, pp. 181-202

Paul Erdkamp, “Polybius and Livy on the Allies in the Roman Army”, publ. The Impact of the Roman Army (200 B.C. – A.D. 476): Economic, Social, Political, Religious and Cultural Aspects, publ. Brill, 2007

Footnotes:

1. At least 150,000 Athenians (of which 30.000 with civil rights), around 50,000 aliens, and more than 100,000 slaves ↩︎
2. The level of citizenship in the Roman Republic which granted all the rights of Roman citizenship except the right to vote in popular assemblies. ↩︎
3. Polybius, Histories, Book 2.23-4. ↩︎