Julius Caesar and the fall of the republic

Rome's conquests brought enormous wealth, but that wealth was unevenly shared: small farmers struggled to compete with huge slave-worked estates, and ambitious generals built armies personally loyal to them rather than to the state. In 60 BCE, three powerful men -- Julius Caesar, Pompey, and Crassus -- formed an unofficial power-sharing arrangement historians call the First Triumvirate. Caesar then spent nearly a decade conquering Gaul (58-50 BCE), a campaign he described himself in his Commentarii de Bello Gallico, which made him immensely wealthy, popular with the Roman public, and backed by a battle-hardened, loyal army.

When the Senate, alarmed by his growing power, ordered Caesar to disband his army, he instead led his legion across the Rubicon River into Italy in 49 BCE -- crossing an army into Italy itself was illegal for a general, and the phrase "crossing the Rubicon" still means passing a point of no return. Civil war followed, and Caesar defeated Pompey to become Rome's unrivaled leader, eventually declared "dictator for life" in 44 BCE. He introduced real reforms, including the Julian calendar, but many senators, including Brutus and Cassius, feared he intended to become a king outright, and assassinated him on the Ides of March (March 15), 44 BCE. Rather than restoring the Republic, his death triggered still more civil war, ending only when his adopted heir, Octavian, defeated his last rival at the Battle of Actium in 31 BCE and became sole ruler -- the Republic was over in every way but name.