"The ancients preferred discipline to numbers."
"Few men are born brave; many become so
through training and force of discipline."
When the Roman empire was in decline at the end of the 4th century, Flavius Vegetius Renatus (Végèce in french I think) wrote De Re Militari which became the veritable bible with regards the art of war for more than a thousand years. The maxims he recorded may still be heard today but they did little to boost the plight of the Roman armies.
It remains the foremost authority on Roman military systems.
The images here come from an early french publication (in latin). The book was written in 1498 and published by C. Wecheli in Paris in 1535. I have a very strong feeling both that this text includes elements from other works (Elien the Tactician, Frontin's Strategies) and that the many woodcuts incorporate middle ages technologies. I may be wrong - not only am I no expert but I also got quite confused traversing french and english spellings and translations fossicking for background. Nothing written here should ever be regarded as having authority and that is particularly so for this entry (all care taken ... buyer beware etc).