Assassination of Caesar

The Assassination of Caesar was a turning point in the collapse of the Roman Republic: after Julius Caesar was murdered by senators in 44 BC, the republic was never restored. The succession of conflicts that followed ended with Augustus ruling alone and establishing the Roman Empire, a political transformation that the book connects to Rome’s eventual decline.

Political Crisis Before the Assassination

The assassination followed a long struggle over land, political influence, and the distribution of power in the Roman Republic. Tiberius Gracchus and his brother Gaius had attempted to reform land distribution and other aspects of Roman society; both were killed after confronting powerful landowners and senatorial interests. The conflict resurfaced over the following century, including in the Social War of 91–87 BC. Lucius Cornelius Sulla suppressed demands for change and curtailed the powers of the plebeian tribune, while the same tensions helped build popular support for Julius Caesar in his conflict with the Senate.

In 49 BC, Caesar crossed the Rubicon, the river separating Cisalpine Gaul from Italy, and moved his legion into Italy. The book identifies this act as the overthrow of the political institutions at the core of the republic. Rome fell to Caesar, and another civil war followed. His victory did not settle the conflict: in 44 BC, senators led by Brutus and Cassius murdered him.

Assassination and Renewed Civil War

Caesar’s murder was followed by another civil war, this time between his supporters—particularly Mark Antony and Octavian—and his opponents. The assassination therefore did not restore the old political balance or bring the struggle over republican power to a close. Instead, it formed one link in an escalating sequence: the republic’s institutions had already been challenged by Caesar’s march on Rome, and his death left a further contest over who would command the political order.

After defeating Caesar’s opponents, Mark Antony and Octavian turned against one another. Octavian emerged victorious at the Battle of Actium in 31 BC. By the following year, he ruled Rome alone, beginning a period of personal rule that lasted forty-five years. Known after 28 BC as Augustus Caesar, he established the Roman Empire, though he preferred the title princeps and called his regime the Principate.

From Republic to Empire

The book treats the assassination as part of a wider institutional transition, rather than as an isolated act of violence. Caesar’s crossing of the Rubicon and murder were successive breaks in a sequence that made the republic impossible to recreate. The later victory of Octavian and his sole rule consolidated that transformation: a republic, already tilted toward senators and other wealthy Romans but not yet an absolutist regime, gave way to political power concentrated in a single position.

The consequences extended beyond the form of government. The partially inclusive institutions associated with the republic had helped underpin Roman economic success. Under Augustus, political change began to undermine them, with significant economic effects. The book compares this pattern to the Venetian Serrata: an initially political change could reshape economic institutions and the distribution of power over time. By the fifth century AD, the Western Roman Empire had declined economically and militarily and stood on the brink of collapse.

A Critical Juncture, Not an Inevitable Path

The assassination and the political upheavals around it illustrate the book’s idea of a critical juncture: a major event, or convergence of events, that disrupts an existing political and economic balance and can redirect a society’s institutional trajectory. Such turning points can deepen extractive arrangements or open a path toward more inclusive ones; their consequences depend on the institutions and power relations already in place.

That account does not make the outcome predetermined. The book argues that societies’ institutional differences emerge through contingent conflict and gradual institutional drift, and that small differences can become decisive when a disruptive juncture arrives. In Rome, Caesar’s challenge to republican institutions, his assassination, the subsequent civil wars, and Augustus’s eventual rule together mark the transition whose later political and economic consequences shaped the empire’s decline.