Livy mentions a senator named Gaius Julius who wrote a Roman history in Greek about 143 BC. Given the time period, he would probably have been one of the Julii Caesares, most probably a brother of the Sextus Julius Caesar who was consul in 157, and the great-grandfather of the dictator. This is how Drumann regarded the dictator's most likely descent. If his brother was the Sextus Julius Caesar who was consul in 157 BC, then he would be the son of Sextus Julius Caesar, the praetor in 208 BC.
Gaius Julius Caesar (grandfather of the dictator)
The grandfather of the dictator is relatively unknown; he might have been the same Julius Caesar who died while praetor urbanus. Nothing is known of the career of Gaius Julius Caesar, except that he can possibly be identified with a praetor who died suddenly at Rome, according to Pliny; but that may instead have been the Lucius Julius Caesar who held that office in 166 BC. The dictator's paternal grandmother was named Marcia, and through her the family traced its descent from Ancus Marcius, the fourth king of Rome. Gaius and Marcia had at least three children: Gaius Julius Caesar, father of the dictator; Sextus Julius Caesar, consul in 91 BC; and Julia, who married the general Gaius Marius.
The son of Lucius Julius Caesar and Poppilia, Strabo was a promising statesman and a member of the college of pontiffs. He had already earned a good reputation for his oratorical skills when he became a candidate for the consulship in BC 88. Strabo and his half-brother, Lucius, who had been consul two years earlier, became embroiled in the civil war between Marius and Sulla, and they were put to death by the partisans of Marius in 87.
Gaius Julius Caesar (proconsul of Asia in 90s BC)
Gaius Julius Caesar, sometimes distinguished as "the Elder", was the father of the dictator. In 103 or 100 BC, he served on a commission for the distribution of land, which was then awarded mainly to veterans who had served under Marius. Caesar was praetor around 92 BC, and proconsul of Asia for at least two years, although he had never held the consulship. He seems to have departed his province before the Mithridatic War. Subsequently, he chose to lead a quiet life outside Rome. He died suddenly at Pisae in 85 BC. Caesar's wife was Aurelia Cotta. They had two daughters, known as Julia Major and Julia Minor, followed by a son, Gaius Julius Caesar, the future dictator. He was known to have remained a friend of his brother-in-law, Marius.
Gaius Julius Caesar (dictator)
, often referred to as Julius Caesar, or simply Caesar, was born in 100 BC, the youngest child of Gaius Julius Caesar and Aurelia Cotta. Together with Pompeius and Marcus Licinius Crassus, he was part of the first Triumvirate. A brilliant general who inspired his men, Caesar conquered Gaul, won the Civil War, and instituted various civil and social reforms at Rome. Named dictator in perpetuity, Caesar was assassinated by a group of senators on the Ides of March, 44 BC. The years after his death saw the demise of the Roman Republic, and the establishment of the Roman emperors.
Born Gaius Octavius, the grandnephew of the dictator was adopted by will as his son and heir, becoming Gaius Julius Caesar Octavianus. After avenging himself on his uncle's murderers and political opponents, Octavian and his allies formed the Second triumvirate. After defeating his former friend, Marcus Antonius, at the Battle of Actium in 31 BC, Octavian became the sole master of the Roman world. Four years later, the Senate granted him the title of Augustus, which ever after signified the holder of imperial authority. Augustus maintained the outer forms of the Republic, while at the same time concentrating nearly the full power of the state in his own person. He was the founder of the Julio-Claudian dynasty of emperors, which endured for more than ninety years.
Gaius Julius Caesar (son of Agrippa)
Born Gaius Vipsanius Agrippa in 20 BC, he was the son of Marcus Vipsanius Agrippa and Julia the Elder, and grandson of Augustus. As the emperor had no sons, he adopted Gaius, who became Gaius Julius Caesar, and his brother, Lucius, in the hope that they would succeed him. But he died in AD 4, two years after Lucius Caesar.
Gaius Julius Caesar Germanicus was the son of Germanicus and Agrippina the Elder. He succeeded to the empire on the death of Tiberius, and enjoyed a brief period of popularity and admiration. This faded as his inclination toward cruelty and capriciousness became increasingly apparent. He was assassinated in AD 41.