INTRODUCING THE PRINCIPATE 5were intended to hold the fort until a grandson became of age to rule. This
strategy collapsed through the early deaths of Gaius and Lucius, Julia’s sons,
both adopted by Augustus, and the uncooperative attitude of Tiberius.
Augustus was not fi nished yet. AD 4 saw another round of adoptions,
following the same general principles: the emperor adopted the now
rehabilitated Tiberius and Agrippa Postumus (Julia’s third and sole surviving
son), and required Tiberius, before his own adoption, to adopt Germanicus
(nephew of Tiberius and son of the elder Drusus), who now counted as
brother to Tiberius’ own son (the younger Drusus).^3 Germanicus was now
betrothed to Agrippina, daughter of Julia, so his children had Julian blood.
In the event, of those whose names were ‘in the ring’ in the last years of
Augustus, only Tiberius was destined to rule. Postumus was exiled (in 7) and
assassinated (in 14, on the death of Augustus), and Germanicus died fi ve
years into Tiberius’ reign (in 19). It is deeply ironic that Augustus’ reign- long
obsession with the succession of a Julian bore fruit in the enthronement of,
fi rst, the mentally unstable (or totally irresponsible) son of Germanicus,
Gaius Caligula, and Nero, son of Agrippina and adoptive son of her husband
Claudius, whom he followed as emperor in 54. Nero’s reign degenerated
after a promising start. He was panicked into suicide, following military
rebellion, and the curtains fell on the Julio-Claudian dynasty (in 68). On the
positive side, one could claim that Augustus’ prolonged dynastic scheming
was a success, consolidating rather than undermining the new regime. It
gave Rome Tiberius as emperor, who for much of his reign of 33 years
proved capable and loyal to the founding princeps, and Claudius, brother of
Germanicus (and no blood relative of Augustus),^4 who was regarded by all,
including Augustus, as quite unsuited for the job, but turned out to be a
competent ruler. It helped too that the transition from Augustus to Tiberius
was a relatively easy one, and that it took place in the senate- house rather
than on the battlefi eld. It had clearly been Augustus’ intention that the
senate and the Roman people should play a central role in sanctioning his
choice of a successor.
This convenient arrangement could be upset from two main quarters: the
legions and the praetorian guard. There was mutiny in the German armies
in 14, put down with some diffi culty by Germanicus: many in the army and
in Rome would have preferred this charismatic prince to Tiberius as emperor.
Drusus dealt more effectively with mutiny in the Danube legions. The
senatorial decree of 20 condemning Piso shows the senate looking timorously
over its shoulder at the army, urging it to continue to back the domus
Augusta , in the knowledge that ‘the safety of our empire is placed in the
custody of that house’.^5 It was only with the crumbling of the dynasty in the
last years of Nero that the armies stepped into the vacuum.
The other potentially disruptive factor, alongside the frontier armies, was
the praetorian guard. Its status and power rose signifi cantly under Tiberius,
culminating in the dangerous ascendancy permitted its prefect Sejanus. In
his will Tiberius left each guardsman 500 sesterces. Gaius’ accession was