L. Julius Cæsar, who appears as lieutenant of the great Cæsar only at the end of the war of Gaul, belonged to the same family as himself; he was a son of L. Julius Cæsar, consul in the time of the war against the Marsi, who was assassinated by Fimbria, and brother of Julia, mother of Mark Antony. He stood for the ædileship without success (Cicero, Orat. pro Plancio, 21), was more fortunate in his petition for the consulship, and exercised that high magistracy in 690. (Cicero, Orat. pro Murena, 34; Epist. ad Atticum, I. 1, 2. – Dio Cassius, XXXVII. 6.) He was, with Cæsar, the year after, one of the judges (duumvir perduellionis) in the trial of C. Rabirius. (Dio Cassius, XXXVII. 27.) When the Senate was deliberating on the conspiracy of Catiline, the relationship which united him with P.Lentulus did not prevent him from voting for his condemnation to death. After the war of Gaul, he returned to Rome, and, in the year 707, Mark Antony invested him with the functions of prefect of the town; he was then very aged. (Dio Cassius, XLII. 30.) After Cæsar had been assassinated, L. Cæsar withdrew from the party of Antony, although the latter was his nephew, for which he has been praised by Cicero. (Epist. Familiar., XII. 2.) But his opposition softened down afterwards, and he rejected the proposal to declare war against the ancient lieutenant of Cæsar, made by the great orator. (Cicero, Philippica, VIII. 1; Epist. Familiar., X. 28.) This was the effect of the influence exercised upon him by his sister Julia, to whom he owed his safety in the proscription which followed the conclusion of the triumvirate. (Appian, Civil Wars, IV. 12. – Plutarch, Cicero, 61; Antony, 20. – Floras, IV. 6. – Velleias Paterculus, II. 67.) Nothing is known concerning his after life.