Directly beneath the legatus were a half-dozen or so
military tribunes
, one of them a young man of the senatorial class called the
broad stripe tribune
after the broad senatorial stripe on his tunic. This relatively inexperienced man – it would have been his first official position – acted as the legion’s second-in-command, despite being a relatively tender age when compared with the men around him. The remainder of the military tribunes were
narrow stripes
, men of the equestrian class who usually already had some command experience under their belts from leading an auxiliary cohort. Intriguingly, since the more experienced narrow-stripe tribunes effectively reported to the broad stripe, such a reversal of the usual military conventions around fitness for command must have made for some interesting man-management situations. The legion’s third in command was the camp
prefect
, an older and more experienced soldier, usually a former centurion deemed worthy of one last role in the legion’s service before retirement, usually for one year. He would by necessity have been a steady hand, operating as the voice of experience in advising the legion’s senior officers as to the realities of warfare and the management of the legion’s soldiers.
Reporting into this command structure were ten
cohorts
of soldiers, each one composed of a number of eighty-man
centuries
. Each century was a collection of ten
tent parties
– eight men who literally shared a tent when out in the field. Nine of the cohorts had six centuries, and an establishment strength of 480 men, whilst the prestigious
first cohort
, commanded by the legion’s
senior centurion
, was composed of five double-strength centuries and therefore fielded 800 soldiers when fully manned. This organization provided the legion with its cutting edge: 5,000 or so well-trained heavy infantrymen operating in regiment and company sized units, and led by battle-hardened officers, the legion’s centurions, men whose position was usually achieved by dint of their demonstrated leadership skills.
The rank of
centurion
was pretty much the peak of achievement for an ambitious soldier, commanding an eighty-man century and paid ten times as much as the men each officer commanded. Whilst the majority of centurions were promoted from the ranks, some were appointed from above as a result of patronage, or as a result of having completed their service in the
Praetorian Guard
, which had a shorter period of service than the legions. That these externally imposed centurions would have undergone their very own ‘sink or swim’ moment in dealing with their new colleagues is an unavoidable conclusion, for the role was one that by necessity led from the front, and as a result suffered disproportionate casualties. This makes it highly likely that any such appointee felt unlikely to make the grade in action would have received very short shrift from his brother officers.
A small but necessarily effective team reported to the centurion. The
optio
, literally ‘best’ or
chosen man
, was his second-in-command, and stood behind the century in action with a long brass-knobbed stick, literally pushing the soldiers into the fight should the need arise. This seems to have been a remarkably efficient way of managing a large body of men, given the centurion’s place alongside rather than behind his soldiers, and the optio would have been a cool head, paid twice the usual soldier’s wage and a candidate for promotion to centurion if he performed well. The century’s third-in-command was the
tesserarius
or
watch officer
, ostensibly charged with ensuring that sentries were posted and that everyone know the watch word for the day, but also likely to have been responsible for the profusion of tasks such as checking the soldiers’ weapons and equipment, ensuring the maintenance of discipline and so on, that have occupied the lives of junior non-commissioned officers throughout history in delivering a combat-effective unit to their officer. The last member of the centurion’s team was the century’s
signifer
, the
standard bearer
, who both provided a rallying point for the soldiers and helped the centurion by transmitting marching orders to them through movements of his standard. Interestingly, he also functioned as the century’s banker, dealing with the soldiers’ financial affairs. While a soldier caught in the horror of battle might have thought twice about defending his unit’s standard, he might well also have felt a stronger attachment to the man who managed his money for him!
At the shop-floor level were the eight soldiers of the tent party who shared a leather tent and messed together, their tent and cooking gear carried on a mule when the legion was on the march. Each tent party would inevitably have established its own pecking order based upon the time-honoured factors of strength, aggression, intelligence – and the rough humour required to survive in such a harsh world. The men that came to dominate their tent parties would have been the century’s unofficial backbone, candidates for promotion to watch officer. They would also have been vital to their tent mates’ cohesion under battlefield conditions, when the relatively thin leadership team could not always exert sufficient presence to inspire the individual soldier to stand and fight amid the horrific chaos of combat.
The other element of the legion was a small 120-man detachment of
cavalry
, used for scouting and the carrying of messages between units. The regular army depended on auxiliary
cavalry
wings
, drawn from those parts of the empire where horsemanship was a way of life, for their mounted combat arm. Which leads us to consider the other side of the army’s two-tier system.
The
auxiliary cohorts
, unlike the legions alongside which they fought, were not Roman citizens, although the completion of a twenty-five-year term of service did grant both the soldier and his children citizenship. The original auxiliary cohorts had often served in their homelands, as a means of controlling the threat of large numbers of freshly conquered barbarian warriors, but this changed after the events of the first century ad. The Batavian revolt in particular – when the 5,000-strong Batavian cohorts rebelled and destroyed two Roman legions after suffering intolerable provocation during a recruiting campaign gone wrong – was the spur for the Flavian policy for these cohorts to be posted away from their home provinces. The last thing any Roman general wanted was to find his legions facing an army equipped and trained to fight in the same way. This is why the reader will find the auxiliary cohorts described in the
Empire
series, true to the historical record, representing a variety of other parts of the empire, including Tungria, which is now part of modern-day Belgium.
Auxiliary infantry was equipped and organized in so close a manner to the legions that the casual observer would have been hard put to spot the differences. Often their armour would be mail, rather than plate, sometimes weapons would have minor differences, but in most respects an auxiliary cohort would be the same proposition to an enemy as a legion cohort. Indeed there are hints from history that the auxiliaries may have presented a greater challenge on the battlefield. At the battle of Mons Graupius in Scotland, Tacitus records that four cohorts of Batavians and two of Tungrians were sent in ahead of the legions and managed to defeat the enemy without requiring any significant assistance. Auxiliary cohorts were also often used on the flanks of the battle line, where reliable and well drilled troops are essential to handle attempts to outflank the army. And while the legions contained soldiers who were as much tradesmen as fighting men, the auxiliary cohorts were primarily focused on their fighting skills. By the end of the second century there were significantly more auxiliary troops serving the empire than were available from the legions, and it is clear that Hadrian’s Wall would have been invalid as a concept without the mass of infantry and mixed infantry/cavalry cohorts that were stationed along its length.
As for horsemen, the importance of the empire’s 75,000 or so
auxiliary cavalrymen
, capable of much faster deployment and manoeuvre than the infantry, and essential for successful scouting, fast communications and the denial of reconnaissance information to the enemy cannot be overstated. Rome simply did not produce anything like the strength in mounted troops needed to avoid being at a serious disadvantage against those nations which by their nature were cavalry-rich. As a result, as each such nation was conquered their mounted forces were swiftly incorporated into the army until, by the early first century bc, the decision was made to disband what native Roman cavalry as there was altogether, in favour of the auxiliary cavalry wings.
Named for their usual place on the battlefield, on the flanks or ‘wings’ of the line of battle, the cavalry cohorts were commanded by men of the equestrian class with prior experience as legion military tribunes, and were organized around the basic 32-man
turma
, or squadron. Each squadron was commanded by a
decurion
, a position analogous with that of the infantry centurion. This officer was assisted by a pair of junior officers: the
duplicarius
or
double-pay
, equivalent to the role of optio, and the
sesquipilarius
or
pay-and-a-half
, equal in stature to the infantry watch officer. As befitted the cavalry’s more important military role, each of these ranks was paid about 40 per cent more than the infantry equivalent.
Taken together, the legions and their auxiliary support presented a standing army of over 400,000 men by the time of the events described in the
Empire
series. Whilst this was sufficient to both hold down and defend the empire’s 6.5 million square kilometres for a long period of history, the strains of defending a 5,000-kilometre-long frontier, beset on all sides by hostile tribes, were also beginning to manifest themselves. The prompt move to raise three new legions undertaken by the new emperor Septimius Severus in 197 ad, in readiness for over a decade spent shoring up the empire’s crumbling borders, provides clear evidence that there were never enough legions and cohorts for such a monumental task. This is the backdrop for the
Empire
series, which will run from 182 ad well into the early third century, following both the empire’s and Marcus Valerius Aquila’s travails throughout this fascinatingly brutal period of history.