04-27-2021, 12:10 AM
I've made some estimates for the infantry frontages in my article "Roman Infantry Tactics in the Mid-Republic: A Reassessment," based on the doctrinal frontages of Hellenistic forces in various battles (feel free to DM me with an email to request an offprint).
For the infantry frontages, between 350-500 meters for a 4200-5200 legion or similar sized ala. Total infantry frontage of a consular army (2 legions and 2 ala) would therefore be 1400-2000 meters.
Cavalry frontages are difficult, because cavalry formations themselves were more fluid. The 30 man turma seems best disposed to 3 files of 10 riders (8 deep was not uncommon for the Greeks). If we give each horse 2 meters, the, 600 Roman cavalry might take up 120 meters; allied cavalry varied, but let's just use 900 as a round number, so 180 for the allies: 400 meters total. But a lot more uncertainty here: less clear how much space per horse, how much space between formations, etc.
Still, very roughly a consular army needed around 1800-2400 meters (1.2-1.5 miles). Plenty of uncertainty, but the general magnitude is not implausible; you could certainly give the cavalry more room if you wanted. And many consular armies also had thousands of auxiliaries attached, which could extend the line even further.
Obviously, the army could narrow considerably if necessary, either by eliminating space between the maniples or by stacking units on top of one another; the consular army at Tunis in 255, for example, reportedly had a very narrow front--Roman tactics were flexible!
For the infantry frontages, between 350-500 meters for a 4200-5200 legion or similar sized ala. Total infantry frontage of a consular army (2 legions and 2 ala) would therefore be 1400-2000 meters.
Cavalry frontages are difficult, because cavalry formations themselves were more fluid. The 30 man turma seems best disposed to 3 files of 10 riders (8 deep was not uncommon for the Greeks). If we give each horse 2 meters, the, 600 Roman cavalry might take up 120 meters; allied cavalry varied, but let's just use 900 as a round number, so 180 for the allies: 400 meters total. But a lot more uncertainty here: less clear how much space per horse, how much space between formations, etc.
Still, very roughly a consular army needed around 1800-2400 meters (1.2-1.5 miles). Plenty of uncertainty, but the general magnitude is not implausible; you could certainly give the cavalry more room if you wanted. And many consular armies also had thousands of auxiliaries attached, which could extend the line even further.
Obviously, the army could narrow considerably if necessary, either by eliminating space between the maniples or by stacking units on top of one another; the consular army at Tunis in 255, for example, reportedly had a very narrow front--Roman tactics were flexible!
