INTRODUCING THE PRINCIPATE 7emperors. In the telling words of Cassius Dio, contemporary historian and
senator, the kingdom of gold gave way to one of iron and rust (Dio 71.36.4).
Commodus as sole ruler (from 180), in his multiple excesses and self-
glorifi cation, recalled or outdid the last of the Julio-Claudians, Nero. The
outcome was predictable: the violent death of an emperor, civil war, and the
emergence of a new strong man, Septimius Severus (193). Severus made his
two sons Caracalla and Geta co- emperors, but the Severan dynasty never
recovered from its bloody beginning, and failed to establish a stable
relationship with the aristocracy, or indeed the military, on which it
depended. In this period the initiative in the appointment of emperors passed
from the senate to the army and the praetorian guard. A praetorian prefect
(and equestrian), Macrinus, engineered the murder of Caracalla (in 217)
and himself reigned as emperor for fourteen months, in breach of all
precedent.^8
In 235 the Rhine army declared Maximinus to be emperor and killed the
reigning emperor, Severus Alexander, last of the Severans and a distant
cousin of the founder of the dynasty, together with his mother and entourage.
There followed a chaotic period of around half a century up to the accession
of Diocletian (284), in which the army created and removed emperors. Few
emperors lasted long. Constant warfare against foes both external and
internal drew them into the front line, exposing them to the risk of premature
death. More than twenty emperors or pretenders are known from this
period, though some are mere names, such as Gaius Domitianus, proclaimed
Augustus (as two coins confi rm) and quickly eliminated by Aurelian in 271.^9
It was logical that most emperors of the period were soldiers and that they
hailed from the Balkans, a major recruiting ground for the army. Capable
generals had to be in charge if the empire was to survive. Diocletian
staunched the fl ow of usurpers to a degree by co- opting potential rivals as
colleagues in the Tetrarchy, but after his retirement (in 305) there was no
one with suffi cient authority or foresight to prevent the empire sliding into
six years of contested ascendancy and civil war. Constantine, the ultimate
victor, had no interest in sharing power, and his plans for the succession
revolved around the hereditary principle.
If the empire survived the travails of the third century, the Principate did
not.^10 Late Roman Emperors (for the late empire had certainly arrived by
the end of the third century) were absolute monarchs. The carefully contrived
formula that Augustus had worked out in order to justify and legitimate his
domination of the state had served its term.
The powers of the emperor
Julius Caesar broke with Republican tradition and paid the penalty.^11
Augustus did not follow his example. He presented himself as a magistrate
among magistrates, superior to the rest only in as much as his personal