Imperium covers the years after the rule of Lucius Cornelius Sulla, whose rivalry with fellow general Gaius Marius ultimately led to Sulla’s rise to dictatorship. While this was a formal Roman office, it was intended for acute emergencies. Sulla, however, used the position to further a political agenda of shoring up aristocratic power. When he retired from power in 79 BCE, he left behind a constitutional settlement designed to entrench the authority of the Senate, traditionally the domain of Rome’s wealthiest and most elite families: He stripped the tribunes, officials elected to represent the commoners (or “plebians”) of most of their powers, doubled the size of the Senate, reorganized the courts to give senators a monopoly on jury duty, and proscribed his enemies en masse. The settlement held badly. By the year of Cicero’s first appearance in the novel, the rebel general Sertorius was still fighting Roman forces in Spain, the revolt of the enslaved man Spartacus would soon erupt across Italy, and the eastern Mediterranean was effectively governed by pirates operating from coastal strongholds in Cilicia and Crete. The political response, repeatedly, was the special command: A single magistrate granted unprecedented military authority for an unprecedented length of time, justified each time by a specific emergency.

General Pompey, a key player in the novel, received such a command against Sertorius in 76 BCE, against the pirates in 67 (the lex Gabinia at the center of Imperium’s second part), and against Mithradates, a king in what is now Turkey, in 66 (the lex Manilia, which Cicero supports from the platform of the rostra in his first speech there). Each grant was justified as an emergency measure; each enlarged the precedent for the next. The same period saw the joint consulship (Rome’s highest elected office) of Pompey and his fellow general Crassus in 70 BCE, the restoration of the tribunes’ powers under that consulship, the rise of the young Julius Caesar, and the agrarian agitation that would erupt fully in Caesar’s own first consulship in 59. Cicero’s election to the consulship for 63 BCE, where Imperium ends, places him at the head of a Republic whose constitutional machinery still operates but whose decisive arrangements are now made between a handful of generals and financiers. The Catilinarian conspiracy of 63, the subject of Harris’s second Cicero novel, follows directly from the bargain with the aristocrats that closes the present book. Imperium thus leaves Cicero at the peak of constitutional office, with the men who actually direct events (Pompey in the East, Caesar gathering populist support, Crassus controlling much of Roman finance) operating largely outside the magistracies he has just attained.