Nero Julius Caesar was the adopted grandson and heir of the Roman Emperor Tiberius, alongside his brother Drusus. Born into the prominent Julio-Claudian dynasty, Nero was the son of Tiberius' general and heir, Germanicus. After the deaths of his father and of Tiberius' son, Drusus the Younger, Nero and his brother Drusus were adopted together by Tiberius in September AD 23. As a result of being heirs of the emperor, he and his brother enjoyed accelerated political careers.

Tiberius Julius Caesar Augustus was Roman emperor from AD 14 until 37. He succeeded his stepfather Augustus, the first Roman emperor. Tiberius was born in Rome in 42 BC to Roman politician Tiberius Claudius Nero and his wife, Livia Drusilla. In 38 BC, Tiberius' mother divorced his father and married Augustus. Following the untimely deaths of Augustus' two grandsons and adopted heirs, Gaius and Lucius Caesar, Tiberius was designated Augustus' successor. Prior to this, Tiberius had proved himself an able diplomat, and one of the most successful Roman generals: his conquests of Pannonia, Dalmatia, Raetia, and (temporarily) parts of Germania laid the foundations for the empire's northern frontier.