By the time Julius Caesar stepped in front of the Roman Senate on the Ides of March in 44 B.C., the nearly 500-year-old Roman Republic had been ailing for years. Wealth inequality, political gridlock and civil wars had all weakened the republic in the century prior to Caesar’s ascension to power.

Caesar’s increasingly autocratic reign further threatened the republic. He bypassed the Senate on important matters, controlled the treasury and earned the personal loyalty of the republic’s army by pledging to give retiring soldiers property from public land or use his personal fortune to buy it himself, according to Edward Watts, author of Mortal Republic: How Rome Fell Into Tyranny. He emblazoned his image on coins and reserved the right to accept or reject election results for lower offices. As Caesar transacted public business from a gold-and-ivory throne, rumors swirled that he would declare himself king.

In the first weeks of 44 B.C., Caesar was proclaimed “dictator for life.” His life, though, wouldn’t last much longer.

Fearful that the concentration of absolute power in a single man threatened the republic’s democratic institutions, dozens of senators who called themselves the “Liberators” plotted to kill the dictator. On March 15 in 44 B.C., Caesar was stabbed 23 times by conspirators who believed themselves to be saviors of liberty and democracy. Instead, the daggers they thrust into Caesar dealt a fatal blow to the already wounded Roman Republic.

One of the assassination’s leading planners, Marcus Junius Brutus, had prepared to deliver a speech celebrating the Roman Republic’s restoration right after Caesar’s murder. He was shocked to find that outrage, rather than praise, greeted news of the dictator’s killing. If Caesar had been an autocrat, the lower and middle classes didn’t seem to mind as they benefitted from his radical reforms such as the cancellation of debts and adjustment of the tax code.

Instead of stabilizing the Roman Republic, the assassination plunged it into another civil war as Caesar’s supporters battled the assassins and then each other. Although former deputy Mark Antony positioned himself as Caesar’s rightful successor by delivering a powerful funeral oration, the slain ruler had pre-empted that outcome. In his will, Caesar had named his sickly, 18-year-old great-nephew Octavian as his primary heir and provided for his adoption.

Octavian quickly amassed a private army and outbid Antony for the support of several legions. The forces of the two competing leaders clashed until Octavian and Antony called a truce and agreed to share power with another of Caesar’s former deputies, Lepidus, in the Second Triumvirate. “He was a cunning, ruthless politician who knew how to play both sides,” Barry Strauss, author of Ten Caesars: Roman Emperors from Augustus to Constantine, says of Octavian.

Mary Beard, author of SPQR: A History of Ancient Rome, writes that the triumvirate’s main achievement was a “new round of mass murder.” Octavian and Antony brutally purged the republic’s leadership by killing their enemies and potential rivals. After speaking ill of Antony, Cicero was killed by soldiers loyal to Caesar’s deputy, and his head and right hand were placed on display in the Roman Forum. Avenging Caesar’s murder, Octavian and Antony collaborated to defeat the forces of assassination plot leaders Brutus and Gaius Cassius Longinus in 42 B.C. at Philippi in northern Greece. Tens of thousands died in the bloody battle, and the defeated Brutus and Cassius each committed suicide.

The triumvirate eventually turned on each other. Octavian forced Lepidus into exile and took up arms against Antony, whose affair with Egyptian ruler Cleopatra VII damaged his reputation in Rome and humiliated his wife, who was Octavian’s sister. Octavian positioned himself as the sole defender of Rome from the eastern influence of Egypt, and his navy defeated the combined fleet of Antony and Cleopatra at the Battle of Actium in northern Greece in 31 B.C. after which Antony and Cleopatra each took their own lives.

Having eliminated his rivals and seen the support given to Caesar by the masses, Octavian established absolute rule over the former republic and surpassed the power of his great-uncle. He approved of all candidates standing for election, while the powerless Senate rubber-stamped his decisions. By providing for soldiers’ retirements, he ensured their personal loyalty to him. Citizens in towns across Italy and the western Mediterranean were compelled to swear their personal loyalty to Octavian. Throughout Roman territories, coins, statues and even silverware bore his image.

The Senate in 27 B.C. bestowed the title “Augustus” upon Octavian, which according to Roman historian Cassius Dio signified “that he was more than human.” Augustus ruled as Rome’s first emperor—although he never took that title for himself. “He was a very shrewd politician," Strauss says. “He had a lot of tricks, and one of them was to pretend that what was happening wasn’t really happening. He said that he restored the republic and never used the terms dictator or king, instead calling himself Rome’s ‘first citizen.’”

When a crisis of flooding, famine and plague besieged Rome in 22 B.C., citizens did not agitate for a restoration of the republic, but instead locked up a group of senators and threatened to burn them alive if Augustus was not named dictator. They believed that Augustus alone could save them. The freedom they sought was one from war, hunger and chaos.

Reigning for nearly a half-century, Augustus became the longest-serving ruler in Roman history and ushered in two centuries of peace and prosperity known as the Pax Romana. By establishing the Roman Empire, Augustus completed the task his adopted father had started. “It’s a great irony,” Strauss says of those who plotted Caesar’s murder. “They thought they were liberating Rome, but instead they put the nail in the coffin of the free republic.