Augustus’s victory over Mark Antony at the Battle of Actium in 31 BC left him in control of the Roman world after a period of civil war that stretched back to Julius Caesar’s crossing of the Rubicon in 49. Augustus’s unrivalled military power base and personal prestige gave him a supremacy that he was unwilling to relinquish. But how was he to articulate his domination in a manner that would reconcile it to the elites of Rome, who were so necessary for the government of a vast empire? Naked monarchy was anathema to the Romans. To assume the dictatorship was out of the question. Caesar had made it so unpopular that it was abolished on his death. More importantly, a dictatorship ran contrary to the persona Augustus had crafted during his recent war of propaganda with Antony, particularly his respect for Roman tradition and the established rules of political life. In reality master of all, Augustus preferred to exercise his supremacy through legally defined and limited powers that integrated him into the state and distanced him from the tyranny of the triumvirate of which he had been a part.

In a series of settlements between 28 and 19, Augustus formalised his position. He gave up the office of triumvir and received from the Senate a bundle of powers attached to traditional Roman magistracies and the command over four provinces where the bulk of the Roman army was stationed. Control