INTRODUCING THE PRINCIPATE 15(delegated) power, and the honour and material rewards that they derived
therefrom.^34 They warmed to emperors such as Antoninus Pius and Marcus
Aurelius who treated the senate with respect and consulted or, at least,
briefed it on policy issues. In dangerous times they survived and even
prospered because they were judged, rightly, to be safe men. Pliny and
Tacitus moved up the magisterial career ladder under Domitian, while
Cassius Dio is revealed by his own narrative to have entered the senate
under Commodus, risen up the ranks under Septimius Severus and Caracalla,
and served in their council.
Pax et Principatus
The Augustan ‘settlement’ held fast over more than two centuries, there was
continuity in government and administration, and relative peace in the
empire.^35 In order to follow these developments, and to trace continuity and
change in economic life, society and culture in the empire at large – which is
the purpose and raison d’être of this book – one must penetrate well beyond
the canonical literary sources, captivated as they are by the eccentricities,
extravagance and scandalous conduct of individual emperors, court intrigue,
and tortuous emperor–senate relations; one must also take in the evidence
provided by epigraphy, papyrology and material remains, as well as sundry
works of literature. We now set the scene with a brief assessment of the state
of the empire under the Principate.
The Principate brought stability and a measure of unity to a greatly
enlarged empire. Reign length is one simple index of the stability of the
regime, a second is the ease of transition from one emperor to another, and
a third the prevalence of peace.
The reigns of Augustus and Tiberius, together taking up almost two-
thirds of a century, put the new regime on fi rm foundations (27 BC – AD 37).
On the strength of their efforts the Julio-Claudian dynasty survived for three
further decades (until 68). The Flavian dynasty, father and sons, ruled
without interruption for the best part of three decades (69–96). The reigns
of the fi ve emperors who held power from Trajan through the Antonine
period cover a period of almost a century (98–192), averaging two decades
per emperor, more or less. If we leave out the last Antonine emperor,
Commodus (a 16-year reign), these emperors straddled a period long
regarded by historians (from Cassius Dio to Edward Gibbon and beyond) as
the most felicitous in Roman imperial history. In the Severan period turnover
at the top quickened (there were eleven emperors between 193 and 235) but
still fell far short of the speed of ruler- change that characterised the mid- to-
late third century, the transitional period between Principate and late empire.
The twenty- one-year reign of Diocletian (who shared power with three
fellow- tetrarchs), matching the durability of the Antonine monarchs, points
to his successful restoration and renewal of the empire following the