Sunday, October 19, 2014

eBook Review: Military Institutions of the Romans (De re militari)

Publius Flavius Vegetius RenatusMilitary Institutions of the Romans (De re militari)

  • Product Details

    • File Size: 191 KB
    • Print Length: 114 pages
    • Publisher: (April 30, 2011)
    • Sold by: Amazon Digital Services, Inc.
    • Language: English
    • ASIN: B004YTJ4D2 
    • Text-to-Speech: Enabled
    • X-Ray: Not Enabled
    • Lending: Enabled 
    • Average Customer Review: 4.5 out of 5 stars (17 customer reviews)
    • Price: $0.99 

1. Short review:   (Amazon rating: 5 out of 5 stars -- I love it.) I shall read this again.

2. Long review:
2.1. What I liked: The only book on the Roman army by a Roman. Details that I cannot find anywhere else.
Roller-coaster or walk-in-the-park? An absorbing walk in the park.
Good value for the money.

2.2. What I did not like: Not available at Project Gutenberg.

2.3. Who I think is the audience: Military history nuts. Like me.

2.4. Is the book appropriate for children to read?  Yes, if they are military history nuts.

2.5. On the basis of reading this book, will I buy the author's next book? No. Only one other book by Vegetius survives. It is a book on the practice of veterinary medicine -- in Roman times.

2.6. The plot in a nutshell:
     There was no plot. For the Emperor Valentinian, Vegetius summarized the organization, training, and practice of Roman armies from the late republic through the early empire.  
 2.7. Other:
     Scholars argue over which Valentinian Vegetius wrote for. There were three. Given what Vegetius wrote about the military successes of the emperor, I think he must have written for Valentinian I.
     Vegetius wrote at a time when Cataphracts were replacing the Legions as the backbone of the Roman army. At the time he wrote, the subject had more academic interest than practical application.
     Vegetius wrote that the Legions marched 20 miles in 5 hours. This is astonishing. Today's armies quicktime march pace is 3 miles an hour.


     On reflection, I do not believe Vegetius statement that the Legions marched 20 miles in 5 hours. To do that, the Legion needed to maintain a pace of 160 steps to the minute. That is doubletime. That means running.
     In effect, Vegetius claims the Legions ran a Marathon every day.
     Turns out the Roman mile is shorter than the English mile: 1,620 yards versus 1,760 yards. So a Roman mile is 0.92 of an English mile. That means the Legions covered 18.4 English miles in 5 hours.
     That is still a fast pace. This means the Legions covered 108 yards every minute. That translates to 132 paces a minute. Do-able but still fast.

     I thought some more about Vegetius's statement that the Legions marched 20 miles in 5 hours.
     First, Vegetius did not witness this himself. He was clear about that. What he did was summarize the military writings of the ancients. Sort of like the Readers' Digest version of Caesar's Gallic Wars and Tacitus's Histories.
     Second, where does 5 hours come from? Did Vegetius -- and Caesar before him -- think in terms of hours? Or was this period of time inserted by the translator, John Clarke, in 1767? I read Military Institutions of the Romans in English. I have not read it in Latin, have not searched for a Latin edition, and have no plan to do so.
     Let's give this some thought.
     What was a day's march for a Legion?
     A Roman Legion began its day in camp. The Roman camp was a prepared defensive position:
     This illustrates a camp to be used for a long time. On the march, the Romans did not build watchtowers and stockades every day, but they did entrench around their camp and build a glacis. One Roman Legate omitted to build a proper camp when he campaigned against Spartacus. Spartacus led his forces to overrun him at night. The Roman survived. He was tried by the Senate, found guilty of negligence, and exiled from Rome.
     The Romans were serious about building a camp every day.
     I infer that the day began for a typical Legion at sunrise. Each maniple found its own breakfast, some cooking for themselves, others having camp followers do it for them. After breakfast, the men packed and prepared to march. At the sound of horns, each maniple fell in formation. Once formed up, the Legion marched out of camp, horse first, followed by flankers of the first cohort, followed by the first cohort. The first cohort marched at the head of the formation because 1) the first cohort was the most veteran and best able to deal with contingencies in march and 2) the head of the formation encountered less dust.
     This is where Vegetius's statement that the Legion marched for 5 hours comes in. I do not know how the Romans determined that 5 hours had passed, but I shall take Vegetius's statement at face value. I do not mean that the Romans marched exactly 5 hours, but 5 hours give or take a bit.
     I infer that the Romans marched 5 hours without a break and that the 5-hour march was their day's march. I do not know if the lead elements of the horse or the first cohort staked out the next camp, but a 5-hour march left time for the Legion to dig the trench, build the glacis, pitch camp, set the watch, and gather wood and water. After all that, the maniples laid down to dinner. (The Romans reclined to eat. For a minor infraction, a Roman soldier was made to stand while he ate.)
     I infer that the 5-hour march means the Legionnaire ate twice a day: once in the morning before the march and once in the evening after he built the camp.


2.8. Links: Vegetius

2.9. Buy the book:  Military Institutions of the Romans (De re militari)


  1. Looks like a good read. Picking it up now.

    That would be an impressive marching speed. Did that just cover the heavy infantry, or did it include supply train and all?

  2. @Jim Self

    Thank you for your comment.

    The short answer is, yes, the whole Legion moved at that pace, wagons and camp followers all.

    Vegetius did not say, but absent evidence to the contrary, I assume the supply train marched with the infantry. If I recall correctly, each cohort marched as a unit with centuries of infantry in the van, then supply wagons, then centuries of infantry in rearguard. So wagons would have been interspersed among the infantry. I think the auxiliaries and light troops flanked the column. The ambush you see in the movie The Centurion could not happen. The horse answered only to the Legate and rode ahead and wide to scout 1) for the enemy and 2) for a place to camp.

    1. Just making sure to eliminate the qualifiers. :) As you said, that's an impressive marching speed for a fully-equipped ancient fighting force.

      I'll be diving into this one as soon as I finish the current read.