Who was Augustus?

Octavian's rivalry with Antony briefly turned to open conflict when Antony besieged one of Caesar's assassins at Mutina in 43 BC. The Senate, encouraged by Cicero, backed Octavian against Antony, granted the young man senatorial rank and military command, and celebrated his victory at Mutina. But when the Senate then snubbed him, Octavian marched on Rome and forced his own election as consul at just nineteen. He soon reversed course and allied with Antony and Marcus Lepidus, forming the Second Triumvirate in 43 BC, a legally sanctioned three-man dictatorship meant to avenge Caesar and restore order.

The triumvirs opened their rule with proscriptions, officially outlawing around 300 senators and many more equestrians, seizing their property to fund the coming war. Ancient writers disagree on how much blame each triumvir bore, but all profited from eliminating political enemies. In 42 BC the triumvirs defeated Caesar's assassins, Brutus and Cassius, at the Battle of Philippi in Macedonia; both men took their own lives. Afterward the triumvirs divided the Roman world between them, with Antony taking the east, where he allied with and later married Cleopatra of Egypt, while Octavian took the west and the difficult task of settling thousands of discharged veterans on confiscated Italian land.

Tensions among the triumvirs played out through further conflict. Octavian put down a revolt led by Antony's brother and wife at Perusia in 40 BC, fought a long naval war against Sextus Pompey in Sicily that his commander Agrippa finally won in 36 BC, and forced Lepidus into permanent retirement that same year after Lepidus tried to claim Sicily for himself. Meanwhile Antony's alliance with Cleopatra, his divorce of Octavian's sister Octavia, and a widely publicized will favoring his children by Cleopatra gave Octavian the propaganda he needed to brand Antony a traitor to Rome.

In 32 BC the Senate stripped Antony of his future consulship and declared war on Cleopatra. Octavian's commander Agrippa cut off Antony's fleet and supply lines in Greece, and the decisive naval Battle of Actium followed on 2 September 31 BC. Cleopatra's ships withdrew early in the fighting and Antony followed her, leaving his remaining forces to surrender. Less than a year later, after Octavian's forces reached Alexandria, Antony killed himself; Cleopatra did the same shortly after, rejecting the prospect of being paraded through Rome in Octavian's triumph.

Octavian secured his position by ordering the death of Cleopatra's son Caesarion, whom many viewed as Julius Caesar's biological heir and therefore a dangerous rival claim, and by killing Antony's eldest son, while sparing Antony and Cleopatra's younger children. Egypt itself became Octavian's personal possession rather than an ordinary Senate-administered province, governed through an equestrian prefect answerable directly to him, and its enormous wealth went a long way toward settling the debts built up during years of civil war. With Antony and Cleopatra gone, Octavian was left as the unchallenged master of the entire Roman world.

Rather than rule openly as a king or dictator, Octavian engineered a gradual transfer of constitutional authority that preserved the appearance of the old Republic. In January 27 BC he theatrically offered to give up his provinces and armies to the Senate, which responded by asking him to keep control of the most troubled provinces, including Spain, Gaul, Syria, and Egypt, for a ten-year term. This arrangement, later called the First Settlement, left him in command of the great majority of Rome's legions while the Senate retained nominally independent provinces of its own. At the same time the Senate granted him the new title Augustus, meaning the revered one, a term with religious rather than overtly political overtones, and he began styling himself Imperator Caesar, emphasizing his inherited link to the deified Julius Caesar.

A further Second Settlement in 23 BC followed a serious illness that forced Augustus to confront questions of succession and the limits of his own authority. He gave up his continuous hold on the consulship, which opened that office to other senators, but in exchange received lifelong tribunician power, letting him convene the Senate, propose legislation, and veto decisions, along with an enhanced form of proconsular authority that outranked other provincial governors throughout the empire, including inside the city of Rome itself. Over the following years he also took on censor-like powers to review the Senate's membership and public morals, and after the death of Lepidus in 12 BC he assumed the religious office of pontifex maximus. In 2 BC the Senate awarded him the title pater patriae, father of the country.

This carefully staged system, later called the principate, let Augustus govern as an effective autocrat while avoiding the titles of king or dictator that had doomed Julius Caesar. He controlled the treasury, the army, foreign diplomacy, and the city's grain supply, intervened in senatorial provinces when he judged it necessary, and received credit for nearly every Roman military victory because most armies operated under commanders answerable to him. He was also acclaimed imperator by his troops twenty-one times over the course of his reign, and the Senate permitted him alone, with rare exceptions, to celebrate a formal triumph.

Augustus extended Roman territory substantially, completing the conquest of Spain, annexing Egypt, Dalmatia, Pannonia, Noricum, and Raetia, and expanding Roman holdings in Africa. He negotiated the return of military standards lost decades earlier to the Parthian Empire, treating the diplomatic success as a symbolic triumph, and reached a peace treaty with the Kingdom of Kush in Nubia after border fighting in Egypt. His stepsons Tiberius and Drusus led campaigns toward the Rhine and Danube, with Drusus reaching the Elbe River before dying from a riding injury. The clearest setback came in AD 9, when the Germanic leader Arminius destroyed three entire Roman legions under Publius Quinctilius Varus at the Teutoburg Forest, a disaster that led Augustus to abandon further expansion into Germany beyond the Rhine.

Securing an heir proved difficult. Augustus favored first his nephew Marcellus, then his general and son-in-law Agrippa, and later his grandsons Gaius and Lucius, adopting the boys as his own sons. Both grandsons died young, in AD 2 and AD 4, which led Augustus to recall his stepson Tiberius from retirement, adopt him, and gradually grant him powers matching his own. A third grandson, Agrippa Postumus, was eventually exiled and disowned. By the time of his death, Tiberius held proconsular authority equal to that of Augustus himself, making the succession, while never openly declared a hereditary monarchy, effectively settled.

Augustus died at Nola on 19 August AD 14, in the same house where his father had died decades earlier. Ancient historians Tacitus and Cassius Dio both recorded rumors that his wife Livia had poisoned him, though many modern historians treat this as hostile gossip aimed at discrediting Tiberius rather than established fact. His body was carried in procession to Rome and cremated near the mausoleum he had built for his family. A month afterward, the Senate formally declared him a god of the Roman state, joining the ranks of the deified Julius Caesar, and Tiberius succeeded him as emperor.