The Roman Army, 31 BC–AD 337: A Sourcebook

56 The Roman Army
Aurelius Harpocration [enlisted] in the consulship of Agricola and
Clementinus (AD 230); promoted centurion from cavalryman [ _ _ _ ]
[by _ _ _ ] prefect of Egypt on the [5–7] of [month, year].
This is a list of centurions and decurions in order of seniority with details of
their promotion. The unit mentioned in the first part of the papyrus received at
least five new decurions during a year. However this is reasonable if, as seems
likely, it was a milliary ala, which according to Hyginus (On the Fortification
of Camps 16) had twenty-four decurions. The battle of Resaina in which
Timesitheus, Praetorian Prefect of Gordian III, defeated the Persians and reestablished
Roman influence in Mesopotamia, took place in AD 243. The
promotions recorded in the papyrus may indicate the replacement of losses
incurred over the whole campaign, although it is not clear if the text predates
the battle itself. For the appointment of auxiliary centurions, see Gilliam 1957b.
PREFECTS AND TRIBUNES
Equestrians commanded auxiliary units and held the tribunates of the
urban troops and five of the six tribunates in a legion. By the late first
century AD it had been established that these posts were held in a
certain order – prefect of a cohort, military tribune (sometimes a milliary
unit was commanded by a tribune), prefect of an ala – and although
equites were not obliged to hold all three posts (tres militiae), some
spent many years in various military assignments. Equestrian military
officers might be holding their first post or might be experienced soldiers
promoted from the rank of chief centurion (see above, texts nos 90,
94, 95). The promotion of such men not only increased the number of
skilled officers but also fostered a degree of social mobility. The prefect
of engineers (praefectus fabrum) in the late Republic served as a kind
of personal adjutant to a military commander, and although the post
continued to be held by men of equestrian rank with this function
down to the mid-first century AD, it increasingly became a sinecure
held by young equestrians, sometimes as a mark of honour. In addition,
the patronage of senators or army commanders was often important
in securing the advancement of equestrian officers; so the experience
and presumed military ability of an applicant will have been only part
of the reasons for his appointment. Men who had held one or more of
these military posts often went on to occupy a combination of further
posts, from financial procuratorships up to the major prefectures, e.g.,
the corn supply, Egypt, and praetorian guard. At the beginning of the
imperial period most equestrian officers were Italians, often from leading
municipal families. Gradually this predominance declined as equestrians