Drusus Julius Caesar, also called Drusus the Younger, was the son of Emperor Tiberius, and heir to the Roman Empire following the death of his adoptive brother Germanicus in AD 19.

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.