How was a typical legion organized in the late Republic and early Empire?

• A. A thousand infantry with a hundred cavalry
• B. Around 4,000–6,000 infantry in 10 cohorts; plus cavalry; the first cohort often larger
• C. 20,000 infantry divided into four legions
• D. A hundred cohorts of mixed units

Answer: (B)

A legion in the late Republic and early Empire was a large, well-ordered infantry force around 4,000–6,000 men, with a small cavalry component. The infantry was organized into ten cohorts, the first cohort being larger and more elite than the others to provide additional punch and leadership in battle. The remaining nine cohorts were about the same size, each divided into six centuries, with roughly 80 men per century. The first cohort’s centuries were double-strength, giving it extra staying power in hard fighting. In addition to the infantry, a legion carried a modest cavalry contingent—enough for reconnaissance and screening, plus possibly a few further cavalry attached from allied forces when needed. This structure—ten cohorts with a notably larger first cohort and a clear hierarchy from cohort to century—made the Roman legion both formidable in line and flexible in deployment during the late Republic and into the early Empire.