On 15 March 44 BCE, a group of Roman senators surrounded Julius Caesar during a meeting in Pompey's curia and stabbed him to death. They called themselves liberators. They believed the removal of a dictator would restore the Republic. Instead, they opened a new struggle for armies, provinces, money and the right to define Caesar's memory.

The Assassination of Julius Caesar follows the crisis from Marius and Sulla through Gaul, the Rubicon, Pharsalus and Caesar's dictatorship. It reconstructs the conspiracy of Brutus, Cassius and their allies; separates evidence from later drama; and examines the physical setting, sequence and contested words of the Ides of March.

The story continues through Caesar's funeral, Antony's manoeuvres, Cicero's Philippics, Octavian's rise, the triumviral proscriptions and Philippi. Drawing on letters, ancient histories, coins, portraiture and Roman topography, this richly illustrated account explains why killing Caesar could not restore a political system already transformed by military power.