North Carolina (2015) h/b 382pp £54.50 (ISBN 9781469621265

This book examines how the concept of imperium (military command) emerged from Rome’s early history, how it mutated in the late republic and how Augustus used the device to establish the principate.

D.’s thesis is as follows: Rome’s earliest wars tended to be reciprocal raiding with nearby communities. The leaders of the raiding parties or war bands would have been private individuals rather than state officials. Once Rome had gained control of the Latin League, it started fielding larger armies to combat more formidable enemies. Military command gradually became institutionalised. The top magistrates were automatically the top generals. Quite when the terms praetor and consul emerged is debatable. Commanders acquired the authority of the state (conferred through the comitia curiata) and exercised imperium. The imperium of the military commander was absolute within the confines of his military campaign. He could order executions and even the decimation of his entire army, although doing that too often might not be a wise move. Upon returning to Rome, he lost all his powers when he crossed the pomerium, the sacred city boundary. Occasionally, in times of crisis, the Senate appointed a dictator, who exercised imperium both inside and outside the city.

Imperium was essentially different from the power of civil magistrates (potestas). The latter was hemmed in by legal restrictions and rights of appeal. In addition to their imperium, military commanders also possessed auspicium, which was religious authority. They could consult the gods by taking the auspices. This was deemed essential if Rome was going to win, as it usually did.

The term provincia originally meant a task entrusted to a commander. As Rome started to acquire overseas territories, the word came to mean a geographical area which was subject to Roman administration. If the area was turbulent, a governor with consular powers was needed. If it was more peaceful, like Sicily, someone with praetorian powers would do. The expanding Empire gave rise to the need for more magistrates. Rome met that need by the device of prorogation. A formal decision of the people (or later the Senate) enabled a consul or praetor to continue to perform his military responsibilities after the expiry of his office. So, hey presto, there were plenty of pro-consuls and pro-praetors with all the necessary powers to manage provinces. Julius Caesar’s lex Julia formalised the distinction between consular and praetorian provinces. The need to govern provinces, as opposed to just conquering them, added a new dimension to the roles of pro-consuls and pro-praetors. This included taxation and civil administration. A series of laws (summarised in chapter 5) enabled provincial governors who abused their powers to be held to account.

In the last years of the republic, both the first and second triumvirates distributed provinciae amongst their members on a grand scale. This enabled the triumvirs to win military glory and, in the process, massively to extend the Empire. In the period 48-44 BC Caesar made excessive use of dictatorship, in order to hold imperium both inside and outside the city. This worked admirably in the short term, but it made Caesar unpopular and led to his assassination. In 31 BC Octavian tried a different approach. As consul for several years and then as pro-consul, he held imperium over the key provinces. Octavian/Augustus adapted the institutions of the republic in order to secure his position as Emperor.

This book is well researched and full of interest. It assumes general background knowledge of Roman history, but many readers will have that. By focusing on how military commanders used their imperium over the centuries, D. is able to cut out irrelevant material and keep his text within manageable length. I commend it as a valuable contribution to the classicist’s library.

Rupert Jackson—Court of Appeal