Scottish academic Dr. Ross Cowan has put together an impressive summary of the Augustan-era legionary in Osprey's Warrior #71, entitled Roman Legionary 58BC - AD 69. Unlike previous Osprey titles on the Roman Army that tend to recycle old information, Dr. Cowan has been able to benefit from the recent discovery of the site of the Teutoberg Forest battlefield in Germany and subsequent archeological discoveries. Furthermore, while Cowan relies heavily on the standard literary sources - Caesar, Tacitus, Polybius and Josephus - he is able to incorporate some less-used sources as well (e.g. Velleius Paterculus). Overall, this is a fine summary for a young scholar and one that is able to add value to existing collections on the Roman military.
Roman Legionary 58BC - AD 69 consists of a short introduction/chronology, a detailed chart of the 28 Augustan legions, and short sections on the organization/size/command of the legion; enlistment; training; length of service; pay; leadership and morale; belief and belonging; decorations and punishments; dress and appearance; equipment; and daily life on campaign. The section on battle is 12-pages long and discusses more tactical issues. The author also includes a list of relevant websites (thank you!), a glossary of Roman terms (some of which are rather uncommon) and a bibliography. The eight color plates by Angus McBride are excellent and depict: a veteran legionary of Legio XII in 32 BC; a Roman press-gang in Ostia; a Roman squad on the march; four legionary fighting techniques; camp construction; the Battle of Teutoburg Forest in AD 9; a century in battle order; and a legionary in AD 43. The text is also supported by a number of photographs of Roman military artifacts recently excavated in Germany since 1999.
Dr. Cowan does a fine job describing the path of the Roman recruit from enlistment, through training and assignment to a legion. One aspect of the Roman soldier that I had not seen emphasized before was the importance of the balteus (belt) and caligae (military boots). Cowan notes that, "the removal of the balteus stripped a soldier of his military identity; it was confiscated if a soldier was dishonorably discharged." Another interesting distinction that often goes unnoticed is that some Roman troops fought "expediti" without armor while the majority remained armored. Cowan notes that Roman commanders usually preferred to have some troops outfitted as expediti, particularly on route marches where they served as mobile flankers to protect the columns.
In the section on Battle, Cowan notes Roman preference for the "triplex acies" or triple line formation with cohorts deployed in 4-3-3 order. Indeed, much of the modern tactical preference for "two up, one back" harkens back to Caesar's tactical formulae. Cowan's characterizations of Roman battle tactics and formations are heavily influenced by modern research on the subject, such as by Keppie and Goldsworthy. However, the author's assertion that the "century was the primary tactical units of the legion," rather than the cohort, is unsupportable. Cowan's hypothesis, borrowed from an earlier researcher in 1994, is based upon the evidence that the cohort lacked its own commander or standard. This is exceedingly thin evidence for such a controversial hypothesis that controverts Caesar and Tacitus, and demonstrates the danger of modern researchers who "think things to death". No military man from any time in the past 2,000 years would believe that an 80 man, company-size unit would be the primary tactical unit rather than a 300-600 man cohort or battalion size unit. First, a century could not perform independent tactical missions, but a cohort with six cohorts could operate independently and we have the accounts to prove this. Second, Roman military doctrine was based upon the timely use of reserves; a century lacked the size to employ a reserve on a significant enough scale to influence a battle, but a cohort could commit two centuries as a reserve. There is little doubt that the century was the building block for the larger cohorts and legions, but it was not an end unto itself. If Cowan was right and the cohort was merely an administrative entity, then try to imagine the Legion commander controlling 60 centuries on the battlefield without an intermediate level of command - this defies military logic. Nevertheless, this is an excellent summary of the Roman legionary in this period.