Marcus Antonius was born in Rome on 14 January 83 BC into the Antonii, a prominent plebeian family of the Roman nobility.¹⁷¹⁸ His paternal grandfather, of the same name, had served as consul in 99 BC and censor in 97 BC, and was celebrated by Marcus Tullius Cicero as one of the foremost orators of his generation. Antony's father, Marcus Antonius Creticus, was a praetor who was granted an extraordinary command to clear the Mediterranean of pirates, a campaign that ended in failure and his death in Crete around 71 BC.¹⁹ Antony's mother, Julia, was a patrician of the Julii Caesares; she was the daughter of the consul Lucius Julius Caesar and a third cousin to Gaius Julius Caesar.

After his father's death, Julia married Publius Cornelius Lentulus Sura, an ambitious patrician who had been consul in 71 BC before being expelled from the Senate by the censors for moral misconduct.²⁰²¹ Raised along with his younger brothers Gaius and Lucius in Lentulus's household, Antony experienced a severe political trauma in December 63 BC.²²²³ Lentulus became a chief urban leader of the conspiracy of Lucius Sergius Catilina and was summarily executed without trial in the Tullianum prison on the orders of the reigning consul, Cicero.²⁴ Ancient biographers, notably Plutarch, trace Antony's lifelong animosity toward Cicero to the execution of his stepfather.²⁵

During his late adolescence, Antony acquired a reputation in Rome for heavy drinking, gambling, and extravagant living. He formed a close association with the young noble Gaius Scribonius Curio, accumulating debts reported at 250 talents (roughly six million sesterces), and briefly allied himself with the populist street leader Publius Clodius Pulcher. In 58 BC, to escape his creditors and the fallout of his association with Clodius, Antony traveled to Greece, where he studied rhetoric and military exercises in Athens.

The following year, Aulus Gabinius, the Roman proconsul of Syria, recruited Antony to serve as commander of his Gallic and German cavalry. Between 57 and 55 BC, Antony campaigned with distinction in Judaea, where he was the first to scale the fortifications during the sieges of Alexandrium and Machaerus in the suppression of the Hasmonean revolt led by Aristobulus II. In 55 BC, he persuaded Gabinius to march into Egypt to restore the deposed Pharaoh Ptolemy XII Auletes—the father of Cleopatra VII—to the throne. Antony led the vanguard across the Sinai desert, captured Pelusium, and prevented Ptolemy from massacring the garrison's surrendered inhabitants, earning early renown for both tactical daring and clemency toward defeated soldiers.

In 54 BC, through the patronage of his kinsman Julius Caesar and the recommendation of Gabinius, Antony joined Caesar's military staff in Gaul as a legate during the later stages of the Gallic Wars.²⁶ After serving in the suppression of Ambiorix's revolt in northeastern Gaul, Antony returned briefly to Rome with Caesar's backing and was elected quaestor for 52 BC, an office of financial administration that automatically conferred a lifetime seat in the Roman Senate. Immediately after his election, he rejoined Caesar in central Gaul and participated in the decisive siege of Alesia against the Arvernian chieftain Vercingetorix, remaining in Gaul through 51 BC to pacify remaining pockets of resistance.

Returning to Rome in 50 BC as Caesar's principal political agent, Antony was elected to the influential priestly college of augurs—defeating Caesar's conservative opponent Lucius Domitius Ahenobarbus—and was simultaneously elected one of the ten tribunes of the plebs for the year 49 BC. Assuming office in December 50 BC, he used his tribunician powers to defend Caesar against the conservative senatorial faction (the Optimates) led by Cato the Younger and Pompey the Great, who demanded that Caesar disband his legions or be declared an enemy of the state. On 1 January 49 BC, Antony forced the reading of a conciliatory letter from Caesar in the Senate; when the consuls rejected Caesar's proposals and moved to declare martial law via the senatus consultum ultimum, Antony and his fellow tribune Quintus Cassius Longinus interposed their constitutional veto. Threatened with physical violence after the Senate overrode their veto on 7 January, Antony and Cassius fled Rome disguised as slaves to join Caesar's camp at Ravenna, giving Caesar the legal pretext of defending the sacrosanctity of the tribunes when he crossed the Rubicon into Italy.

During the opening campaign of Caesar's civil war, Antony helped secure the Italian peninsula as Pompey and the majority of the Senate evacuated to Greece. When Caesar marched west in the spring of 49 BC to defeat Pompeian armies in Spain, he appointed Antony propraetor in command of the armed forces in Italy. In early 48 BC, despite a strict naval blockade maintained by Marcus Calpurnius Bibulus, Antony successfully ferried four legions of reinforcements across the Adriatic Sea from Brundisium to Epirus, linking up with Caesar prior to the Siege of Dyrrhachium. At the decisive Battle of Pharsalus in Thessaly on 9 August 48 BC, Caesar entrusted Antony with the command of the army's left wing, where they routed Pompey's superior forces.

After Pharsalus, Caesar pursued Pompey to Egypt and was named dictator in absentia, appointing Antony as his magister equitum (Master of the Horse), the dictator's second-in-command and chief administrator of Italy. While an effective battlefield commander, Antony proved heavy-handed in civil administration. Faced with economic crisis in Rome, his colleague as tribune, Publius Cornelius Dolabella, proposed radical legislation for the total cancellation of debts and rents, sparking violent street warfare. Suspecting Dolabella of an affair with his second wife, Antonia Hybrida Minor, Antony marched legionaries into the Roman Forum in 47 BC, slaughtering several hundred citizens to suppress the riots.¹ His public conduct, including his confiscation of Pompey's estates without payment and his public travels with the mime actress Cytheris, displeased Caesar upon the dictator's return later that year. Stripped of official posts, Antony held no public office during 46 and 45 BC, though he married his third wife, Fulvia—the politically influential widow of both Clodius and Curio—during this interval.

By 45 BC, Caesar had reconciled with Antony, designating him as his fellow consul for the year 44 BC and naming him the high priest (flamen) of his new personal cult. During the fertility festival of the Lupercalia on 15 February 44 BC, Antony, running naked through the Forum as leader of the Julian college of priests, publicly offered Caesar a royal diadem intertwined with laurel. When the assembled crowd groaned in disapproval, Caesar pushed the crown away to loud applause; Antony offered it a second time, and Caesar again refused, ordering the diadem dedicated to Jupiter Optimus Maximus on the Capitoline Hill. Whether the episode was a prearranged test of public opinion regarding monarchy or an unsolicited gesture by Antony, it solidified the resolve of sixty senators led by Marcus Junius Brutus and Gaius Cassius Longinus to assassinate the dictator.

As the conspirators planned the murder for the Senate meeting on the Ides of March (15 March) 44 BC, Cassius urged that Antony be killed alongside Caesar, arguing that the surviving consul would pose an immediate military danger. Brutus vetoed the proposal, insisting that executing anything beyond the tyrant himself would taint their tyrannicide as a partisan coup. On the day of the assassination, the conspirator Gaius Trebonius detained Antony in conversation outside the Curia of Pompey while Caesar was stabbed to death inside.

Initially fearing a wider purge of Caesarians, Antony fled home in disguise, but upon learning that the assassins had retreated to the Capitoline Hill without military backing, he swiftly seized the initiative. On the night of 15 March, he persuaded Caesar's widow, Calpurnia, to hand over the dictator's private papers and four thousand talents of silver, while securing the public treasury of seven hundred million sesterces stored in the Temple of Ops. Allied with Marcus Aemilius Lepidus, who brought a legion of troops into the suburbs of Rome, Antony convened the Senate at the Temple of Tellus on 17 March. With Cicero's support, he engineered a pragmatic compromise: the assassins were granted a general amnesty, while all of Caesar's existing laws, appointments, and unratified memoranda (acta) were confirmed as valid, and Caesar was granted a public funeral.

At the funeral in the Forum on 20 March, Antony delivered a eulogy and displayed Caesar's blood-stained toga, reading aloud the dictator's will, which bequeathed his private gardens to the public and three hundred sesterces to every Roman citizen.²⁷ The crowd rioted, cremating Caesar's body in the Forum and attacking the houses of the conspirators, which forced Brutus and Cassius to flee Rome in April. For several months, Antony governed as the preeminent figure in Rome, abolishing the office of dictator forever to appease the Senate while using Caesar's papers—with the help of Caesar's secretary Faberius—to pass laws, sell tax exemptions, and build a personal bodyguard of six thousand veterans.

Declared a public enemy (hostis) by the Senate after Mutina, Antony executed a strategic retreat westward across the Apennines into Transalpine Gaul, enduring severe supply shortages alongside his men. In May 43 BC, he confronted the seven legions of Marcus Aemilius Lepidus at Forum Julii; appearing unshaven in a dark mourning cloak, Antony won the sympathy of Lepidus's soldiers, who opened their camp to him and forced Lepidus into an alliance. Joined soon afterward by the western governors Gaius Asinius Pollio and Lucius Munatius Plancus, as well as Decimus Brutus's defecting legions (leaving Decimus to be captured and executed by a Gallic chieftain), Antony suddenly commanded over twenty legions.

Meanwhile, the deaths of both consuls at Mutina had left Octavian in sole command of the senatorial army. When the Senate attempted to marginalize him and hand command to Decimus Brutus, Octavian marched eight legions on Rome in August 43 BC, seized the consulship, revoked the decrees outlawing Antony and Lepidus, and opened negotiations. In October 43 BC, Antony, Octavian, and Lepidus met on a small river island near Bononia (modern Bologna), surrounded by five legions apiece. On 27 November 43 BC, the Lex Titia was passed in Rome, formally establishing the Triumviri Rei Publicae Constituendae (Triumvirs for the Confirming of the Republic with Consular Power)—known to modern historians as the Second Triumvirate. Unlike the informal First Triumvirate of Caesar, Pompey, and Crassus, this was a legal dictatorship enacted for a five-year term, granting the three men supreme authority to make laws and appoint magistrates without reference to the Senate or people.

To finance forty-three legions for the impending war against Brutus and Cassius in the East and to eliminate domestic opposition, the triumvirs revived the practice of Lucius Cornelius Sulla by issuing edicts of proscription. Up to three hundred senators and two thousand members of the equestrian order were outlawed, their lives forfeited and their properties confiscated. In the horse-trading of names at Bononia, Antony sacrificed his maternal uncle Lucius Julius Caesar (who subsequently escaped through his sister Julia's intervention) in exchange for Octavian abandoning his former ally Cicero. Tracked down by triumviral soldiers near Formiae on 7 December 43 BC, Cicero was beheaded; at Antony's command, the orator's head and hands—which had penned the Philippics—were nailed to the Rostra in the Roman Forum, where Fulvia reportedly pierced Cicero's tongue with her golden hairpins.

During his initial tour of the East in late 41 BC, Antony had summoned Cleopatra VII of Egypt to his headquarters at Tarsus in Cilicia to answer charges that she had aided Cassius prior to Philippi. Arriving up the Cydnus River on a gilded barge with purple sails and silver oars, dressed as the goddess Aphrodite, the twenty-eight-year-old queen quickly won Antony's favor. Seeing in Egypt the richest intact treasury in the Mediterranean and an indispensable logistical base for his planned invasion of the Parthian Empire, Antony spent the winter of 41–40 BC with Cleopatra in Alexandria, where the pair formed a drinking society they called the "Inimitable Livers". Shortly after Antony departed in early 40 BC to confront a Parthian invasion of Syria and the crisis in Italy, Cleopatra gave birth to twins, Alexander Helios and Cleopatra Selene.³⁷

For over three years following the Treaty of Brundisium, Antony remained separated from Cleopatra, living primarily in Athens with Octavia, who bore him two daughters, Antonia Major and Antonia Minor. Meanwhile, Antony's brilliant lieutenant Publius Ventidius Bassus repelled the Parthian invasion of Asia Minor and Syria in 39 and 38 BC, defeating and killing the Parthian crown prince Pacorus I at the Battle of Mount Gindarus. In 37 BC, Antony traveled to Italy and concluded the Treaty of Tarentum with Octavian—mediated in part by Octavia—which renewed the Second Triumvirate for another five-year term until the end of 33 BC. Antony gave Octavian 120 warships to use against Sextus Pompey in exchange for Octavian's promise to send twenty thousand Italian legionaries for Antony's upcoming Parthian campaign, a troop commitment Octavian ultimately failed to fulfill.

Returning east to Antioch in late 37 BC after leaving a pregnant Octavia in Italy, Antony summoned Cleopatra and resumed their union, fathering a third child with her, Ptolemy Philadelphus, born in 36 BC. Simultaneously, Antony conducted a comprehensive administrative reorganization of the Roman East. Rather than expanding direct provincial rule, he established a ring of strong, loyal client monarchs across the frontier: he confirmed Herod the Great on the throne of Judaea, appointed Polemon I over Pontus, Amyntas over Galatia, and Archelaus over Cappadocia, while granting Cleopatra control over Cyprus, parts of Cilicia, Crete, Cyrenaica, and lucrative balsam and cedar territories in the Levant.³⁸ So durable were Antony's administrative appointments among the client kings that Octavian retained nearly all of them intact after Antony's death.

While the Donations of Alexandria transferred little immediate practical governance away from Roman magistrates and client kings, the elevation of Caesarion directly threatened Octavian's foundational political status as the sole legitimate son of the deified Julius Caesar. When the second five-year term of the Triumvirate expired on 31 December 33 BC, the propaganda war between Rome and Alexandria escalated into an open rupture. However, both consuls entering office on 1 January 32 BC, Gnaeus Domitius Ahenobarbus and Gaius Sosius, were staunch partisans of Antony. When Sosius attacked Octavian in the Senate, Octavian surrounded the senate house with armed soldiers, prompting both consuls and more than three hundred senators—roughly a third of the Senate—to flee Italy and join Antony at Ephesus, where Antony established a rival senate.

In the summer of 32 BC, Antony sent formal notices of divorce to Octavia in Rome, evicting her from his family home. Shortly afterward, two prominent defectors from Antony's inner circle, Lucius Munatius Plancus and his nephew Marcus Titius, deserted to Octavian out of resentment over Cleopatra's influence in Antony's war councils and revealed the contents and location of Antony's secret will.⁴¹ Breaking religious custom, Octavian seized the document from the custody of the Vestal Virgins in the Temple of Vesta and read it aloud to the Senate and the public. The clauses of the will—Whether authentic or partially forged by Octavian—confirmed Caesarion as Caesar's true son, bestowed enormous legacies on Antony's children by Cleopatra, and directed that even if Antony died in Rome, his body was to be sent to Alexandria for burial beside the queen.

Public outrage in Italy was immediate, lending credence to rumours that Antony intended to transfer the capital of the Roman Empire from Rome to Alexandria. Stripping Antony of his powers and his designated consulship for 31 BC, Octavian avoided framing the conflict as another fratricidal civil war against a fellow Roman; instead, in late 32 BC, he stood as fetialis priest before the Temple of Bellona and declared a foreign war against Queen Cleopatra VII of Egypt. All of Italy and the western provinces swore a personal oath of allegiance (coniuratio Italiae) to Octavian as their military leader.

Mark Antony was married five times and fathered at least eight known children. His first marriage, attested only in Cicero's Philippics, was to Fadia, the daughter of a wealthy freedman Quintus Fadius Gallus; she bore him children who apparently predeceased him in youth. Around the mid-50s BC, he married his paternal first cousin Antonia Hybrida Minor, daughter of Cicero's former consular colleague Gaius Antonius Hybrida. Before Antony divorced her in 47 BC over her alleged affair with Dolabella, she bore him a daughter, Antonia, who was briefly betrothed to Lepidus's son before marrying the wealthy Greek magnate Pythodoros of Tralles, becoming the maternal grandmother of several client monarchs in Pontus and Thrace.

By his third wife, Fulvia, whom he married in 46 BC, Antony had two sons: Marcus Antonius Antyllus and Iullus Antonius. After the fall of Alexandria in August 30 BC, Octavian ordered the execution of both Caesarion and the adolescent Antyllus—who had been formally enrolled as an adult citizen and therefore posed a potential political rallying point for Caesarian veterans—dragging Antyllus from the shrine of the Divine Julius to be beheaded. All of Antony's remaining children were spared and brought to Rome to be raised by his fourth wife, Octavia Minor, who cared for Fulvia's younger son Iullus alongside her own daughters and Antony's three surviving children by Cleopatra. While Alexander Helios and Ptolemy Philadelphus vanished from historical records after walking in golden chains in Octavian's triple triumph of 29 BC, their sister Cleopatra Selene II was married by Augustus to King Juba II of Mauretania, ruling North Africa with him for two decades. Iullus Antonius rose to become consul in 10 BC before being forced to commit suicide in 2 BC for adultery with Augustus's daughter Julia.

Through his two daughters with Octavia—Antonia Major (born 39 BC) and Antonia Minor (born 36 BC)—Mark Antony became a direct ancestor of the later rulers of the Julio-Claudian dynasty.⁴³ Antonia Major married Lucius Domitius Ahenobarbus (son of Antony's former partisan) and became the paternal grandmother of the Emperor Nero. Antonia Minor married Nero Claudius Drusus, the stepson of Augustus and younger brother of the Emperor Tiberius; she was the mother of the general Germanicus and the Emperor Claudius, the paternal grandmother of the Emperor Caligula and the Empress Agrippina the Younger, and the maternal great-grandmother of Nero.⁴⁴ Thus, although Augustus defeated Antony to establish the principate, three of the five Julio-Claudian emperors—Caligula, Claudius, and Nero—carried Antony's bloodline.

In Rome immediately after 30 BC, the Senate subjected Antony's memory to official condemnation (damnatio memoriae): his statues were torn down, his honors were annulled, his birthday (14 January) was declared an unlucky day (dies vitiosus), and the Antonii family was forbidden from ever again using the praenomen Marcus. Furthermore, because the surviving literary record of the late Republic was shaped overwhelmingly by his two greatest political enemies—Cicero in the Philippics and Augustus in his imperial propaganda—ancient Roman historiography largely portrayed Antony as a brave, generous, and charismatic soldier whose lack of political foresight, fondness for luxury, and subservience to a foreign queen brought about his ruin.

Later classical writers, most notably the Greek biographer Plutarch in his Parallel Lives (where Antony is paired with the Hellenistic king Demetrius I of Macedon) and the historians Appian and Cassius Dio, preserved a rich, complex portrait of his character, emphasizing his theatrical identification with the hero Heracles and the god Dionysus as well as his devotion to his soldiers and to Cleopatra. Modern historians generally reassess Antony as a capable military strategist and pragmatic imperial administrator in the East whose dynastic system of client states laid the institutional foundations for Roman rule in the eastern Mediterranean for the next century, even as his defeat at Actium marked the definitive end of the Roman Republic. In Western literature and dramatic art—ranging from William Shakespeare's tragedies Julius Caesar and Antony and Cleopatra to John Dryden's All for Love and modern cinema—he has endured as the archetypal figure of the soldier-statesman torn between martial duty and romantic passion.