Quick questions on Augustus and the principate: HSC Ancient History

Augustus retained the senate as the central institution of Roman political life, but transformed its membership and function.

The equestrian order (eques) gained importance under Augustus. Equestrians could not hold the senatorial cursus honorum but served in administrative roles.

Augustus's most enduring institutional achievement was the creation of a standing professional army.

Augustus conducted several reviews of the senate (29, 18, and 11 BC). The senate was reduced from around 1,000 to 600 members. Property qualifications were tightened (1 million sestertii).

The senate retained its formal advisory role, debating imperial proposals and electing magistrates (now in form rather than substance). New offices created by Augustus (curators of various public works) gave senators continued employment. Provincial governorships (the senatorial provinces) continued to be allocated by lot from former consuls and praetors.

Augustus presented himself as primus inter pares ("first among equals"), the leading senator. He attended sessions, debated, and accepted senatorial advice. In substance, his maius imperium and tribunician power allowed him to control any senatorial decision; in form, senatorial dignity was preserved.

Equestrian prefects governed Egypt (the most important post, restricted to equestrians and forbidden to senators), commanded the Praetorian Guard, supervised the grain supply (praefectus annonae), and ran the imperial fiscus.

Equestrians served as auxiliary commanders and as junior officers (tribuni angusticlavii) in the legions.

Governed by legates of Augustus (legati Augusti pro praetore). These contained the major legionary garrisons: Spain, Gaul, Syria, Egypt (governed by an equestrian prefect, not a senatorial legate), and other frontier provinces. Augustus controlled around 20 of 28 legions.

Governed by proconsuls allocated by the senate, normally former consuls (Africa, Asia, Macedonia, Bithynia, etc.). These were unarmed or lightly garrisoned interior provinces.

Reduced from around 60 (at the end of the civil wars) to 28, then to 25 after the Teutoburg disaster (AD 9). Stationed in the imperial provinces, with the major concentrations on the Rhine and the Danube frontiers.

Standardised at 20 years (with possible extension to 25). Citizenship was a precondition for legionary service.

A new state treasury for military pay and discharge benefits. Funded initially by Augustus's personal contribution of 170 million sestertii, then by a 5 per cent inheritance tax (vicesima hereditatium) and a 1 per cent sales tax (centesima rerum venalium). The aerarium militare paid for veteran settlement, removing the political problem of generals having to find land for their veterans.

Non-citizen troops supplementing the legions, recruited from across the empire. Service was 25 years; on discharge, auxiliaries received Roman citizenship for themselves and their descendants. The system extended citizenship throughout the empire.

Nine cohorts of around 500 men each. Originally distributed across Italian towns; concentrated in Rome at the Castra Praetoria under Tiberius (AD 23). The Praetorians provided imperial security and a permanent Italian garrison.