Drusus. I. Claudins Nero, commonly called Drusus Senior to distinguish him from his nephew, the son of Tiberius, born in 38, died in 9 B. C. His mother, Livia Drusilla, was divorced from Claudius Tiberius Nero and married to the emperor Augustus three months before the birth of Drusus; and the latter, on the death of his father, was committed to the guardianship of his stepfather. His noble bearing and the liberality of his political sentiments won him early popularity, which was increased by the exploits of his maturer years. After obtaining permission of the senate to fill all offices five years before the legal age, he acted as praetor in place of his brother Tiberius during the latter's absence in Gaul. In 15 he was made quaestor, and in this capacity he was sent against the Rhaetians, who were accused of having plundered subjects and allies of Koine, and whom he defeated as they were about to make a descent upon the plains of Italy. He afterward joined his brother Tiberius, and in conjunction with him thoroughly subdued this formidable tribe. In 13 he was appointed governor of Gaul, and in the following year defeated the Sicam-brians, and afterward the Frisians, penetrating during this expedition as far as the German ocean, which he was the first Roman to reach.
He is supposed to have dug a canal from the Rhine to the Yssel, and thus to have opened a way by the Zuyder Zee to the sea. Returning to Rome in 11, he was made praetor urbanus ; but in the spring he renewed his campaigns in Gaul, subdued the Usipetes and several other tribes, and again returning, was allowed a triumph by the senate. In 10 he won new victories over the German tribes, and in 9 he was elected consul. But even this office could not keep him at Rome. He returned to Gaul, defeated the Catti, Suevi, and Cherus-ci, and penetrated to the Elbe. Here he determined, ostensibly on account of certain portents and omens, to retreat. He set out, but between the Elbe and the Sala (probably the Thuringian Saale) he was killed by the falling of his horse. II. Drusus Caesar, commonly called Drusus Junior, son of the emperor Tiberius by his first wife Vipsania, died A. D. 23. During the life of Germanicus the court was divided between the parties of Germanicus and Drusus, and Tiberius took care not to declare which should succeed him. Drusus had not the dissimulation of his father, but he equalled him in impurity and in cruelty. He was quaestor in A. D. 10, and on his return from Pannonia in 15, whither he had been sent to quell a mutiny of the legions, he was made consul.
He degraded the dignity of his office by his excesses, and Tiberius sent him with the army to Illyri-cum to teach him the art of war and remove him from the dissipations of the city. He successfully interfered in affairs of neighboring Germanic tribes, and an ovation was decreed him by the senate. In 22 he was promoted to the tribunicia potestas, which indicated him as the successor to the empire. Regarding Sejanus as his rival, Drusus one day struck him in the face, and the former persuaded Livia, the wife of Drusus, whose affections he had seduced, to become his murderer. A poison was administered to him which terminated his life after a lingering illness, supposed at the time to be a result of his intemperate habits ; but the crime was confessed eight years afterward by the wife of Sejanus, who was privy to it.