Tiberius was born into one of the most distinguished aristocratic clans in Rome, the Claudii, a family known for producing either exceptional matrons, politicians, and generals, or arrogant and petty people. His father Nero sided against Julius Caesar in the civil war, and as a result, Tiberius, Livia, and the infant Tiberius lived on the run. His first wife was Vipsania Agrippina, with whom he had a son named Drusus. Augustus and Livia forced him to divorce Vipsania Agrippina and instead marry Augustus’s daughter Julia, whom he grew to hate.

After beginning a promising military and political career, Tiberius abruptly retired and left Rome for Rhodes, which infuriated Augustus. Suetonius is unsure of the motive and speculates that Tiberius was either trying to improve his popularity by removing himself from the public gaze, was trying not to seem to compete with Augustus’s grandsons Lucius and Gaius, or was simply trying to get away from Julia. Either way, after two years Tiberius was allowed to return to Rome.

Tiberius resumed his military career by campaigning in Germany, where he gained a reputation for being harsh toward his own soldiers.