At the time of Julia's birth, 39 BC, Augustus had not yet received the title "Augustus" and was known as "Gaius Julius Caesar Divi Filius," though historians refer to him as "Octavian" until 27 BC, when Julia was 11. Octavian divorced Julia's mother the day of her birth and took Julia from her soon thereafter.
 Octavian, in accordance with Roman custom, claimed complete parental control over her. She was sent to live with her stepmother
Livia when she was old enough and learn how to be an aristocrat. Her education appears to have been strict and somewhat old-fashioned. Thus, in addition to her studies,
Suetonius informs us, she was taught spinning and weaving.
Macrobius mentions "her love of literature and considerable culture, a thing easy to come by in that household".
Julia's social life was severely controlled, and she was allowed to talk only to people whom her father had vetted.
 However, Octavian had a great affection for his daughter and made sure she had the best teachers available. Macrobius preserves a remark of Augustus: "There are two wayward daughters that I have to put up with: the Roman commonwealth and Julia."
In 37 BC, during Julia's early childhood, Octavian's friends
Gaius Maecenas and
Marcus Vipsanius Agrippa concluded an agreement with Octavian's great rival
Mark Antony. It was sealed with an engagement: Antony's ten-year-old son
Marcus Antonius Antyllus was to marry Julia, then two years old.
The engagement never led to a marriage because civil war broke out. In 31 BC, at the
Battle of Actium, Octavian and Agrippa defeated Antony and his wife,
Alexandria, they both committed suicide, and Octavian became sole ruler of the
As with most aristocratic Roman women of the period, expectations of Julia focused on marriage and on the resulting family
alliances. Her family first married her off, like many Roman girls, in her early teens. In 25 BC, at the age of fourteen, Julia married her cousin
Marcus Claudius Marcellus, who was some three years older than she. There were rumors that Marcellus had been chosen as Augustus' successor, but Julia's father was not present: he was fighting a war in Spain and had fallen ill. Agrippa presided over the ceremony. Marcellus died in September 23 BC when Julia was sixteen. The union produced no children.
Marriage to Agrippa
In 21 BC, having now reached the age of 18, Julia married Agrippa, a man from a modest family who had risen to become Augustus' most trusted general and friend. This step is said to have been taken partly on the advice of Maecenas, who in counseling him remarked: "You have made him so great that he must either become your son-in-law or be slain."
 Since Agrippa was nearly 25 years her elder, it was a typical arranged marriage, with Julia functioning as a pawn in her father's dynastic plans. There is from this period the report of an infidelity with one
Sempronius Gracchus, with whom Julia allegedly had a lasting liaison (
Tacitus describes him as "a persistent paramour").
 This was the first of a series of alleged adulteries. According to Suetonius, Julia's marital status did not prevent her from conceiving a passion for Augustus' stepson, and thus her stepbrother,
Tiberius, so it was widely rumoured.
The newlyweds lived in a villa in Rome that has since been excavated near the modern
Trastevere. Agrippa and Julia's marriage resulted in five children:
Julia the Younger,
Agrippina the Elder (mother of
Agrippa Postumus (a posthumous son). From June 20 BC to the spring of 18 BC, Agrippa was governor of
Gaul, and it is likely that Julia followed him across the Alps. Shortly after their arrival, their first child Gaius was born, and in 19 BC, Julia gave birth to Vipsania Julia. After their return to Italy, a third child followed: a son named Lucius. In 17 BC, Augustus adopted the newborn Lucius and the three-year-old Gaius.
 He took care of their education personally. Although Agrippa died in 12 BC, Augustus did not adopt the third brother, Marcus Vipsanius Agrippa Posthumus, until AD 4, after the exile of Julia - and after the deaths of both Gaius and Lucius.
Josephus mention that during Julia's marriage to Agrippa, she was travelling to meet Agrippa where he was campaigning, was caught up in a flash flood in
Ilium (Troy), and almost drowned.
 Agrippa was furious, and in his anger he fined the locals 100,000 drachmae. The fine was a heavy blow but no one would face Agrippa to request an appeal. Only after
Herod, king of Judaea, went to Agrippa to request a pardon did he withdraw the fine. In the spring of 16 BC, Agrippa and Julia started a tour through the eastern provinces, where they visited Herod. In October 14 BC, the couple traveled to
Athens, where Julia gave birth to her fourth child, Agrippina.
After the winter, the family returned to Italy. Julia quickly became pregnant again, but her husband died suddenly in March 12 BC in
Campania at the age of 51. He was buried in the Mausoleum of Augustus. Julia named the
posthumous son Marcus in his honor. He was to be known as Agrippa Postumus. Immediately after the boy was born, and while Julia was still in mourning, Augustus had her betrothed
 and then remarried to Tiberius, her stepbrother.
Marriage to Tiberius
After the death of Agrippa, Augustus sought to promote his step-son Tiberius, believing that this would best serve his own dynastic interests. Tiberius married Julia (11 BC), but first had to divorce
Vipsania Agrippina (daughter from a previous marriage of Agrippa), the woman he dearly loved. The marriage was thus blighted almost from the start, and the son that Julia bore him died in infancy.
 Suetonius alleges that Tiberius had a low opinion of Julia's character,
 while Tacitus claims that she disdained Tiberius as an unequal match and even sent her father a letter, written by Sempronius Gracchus, denouncing him.
 By 6 BC, when Tiberius departed for
Rhodes, if not earlier, the couple had separated.
Because Augustus was her legitimate father, having married her mother with conubium, Augustus had
Patria Potestas over her. Patria Potestas lasted until the paterfamilias, Augustus, either died or emancipated his child. Marriage had no effect on Patria Potestas, unless it was
manus marriage which was rare at this point in time.
As the daughter of Augustus, mother (now legally the sister) of two of his heirs, Lucius and Gaius, and wife of another, Tiberius, Julia's future seemed assured to all. Yet in 2 BC she was arrested for adultery and treason; Augustus sent her a letter in Tiberius' name declaring the marriage null and void (Tiberius was at this time on the island of Rhodes and unable to respond quickly). He also asserted in public that she had been plotting against his own life.
 Though at the time Augustus had been passing legislation to promote family values, he likely knew of her intrigues with other men but hesitated for some time to accuse her. Several of Julia's supposed lovers were exiled, most notably Sempronius Gracchus, while
Iullus Antonius (son of
Mark Antony and
Fulvia) was forced to commit suicide. Others have suggested that Julia's alleged paramours were members of her city clique, who wished to remove Tiberius from favour and replace him with Antonius. This would explain the letter, written by Gracchus, asking Augustus to allow Julia to divorce Tiberius.
Reluctant to execute her, Augustus decided on Julia's exile, in harsh conditions. She was confined on the island of
Pandateria, with no men in sight, forbidden even to drink wine.
 The island itself measures less than 1.75 square kilometres (0.68 sq mi). She was allowed no visitor unless her father had given permission and had been informed of the stature, complexion, and even of any marks or scars upon his body.
Scribonia, Julia's biological mother, accompanied her into exile.
 It is said that Augustus would remark of them: "If only I had never married, or had died childless", slightly misquoting
Hector, in the
 Julia's exile cast a long shadow over Augustus's remaining years.
Five years later, Julia was allowed to return to the mainland, though Augustus never forgave her and ordered her to remain in
Rhegium. He explicitly gave instructions that she should not be buried in his
Mausoleum of Augustus.