Augustus adopts Tiberius.

The 0s began on January 1, AD 1 and ended on December 31, AD 9, covering the first nine years of the Common Era.

Gaius Julius Caesar Augustus, also known as Octavian, was the founder of the Roman Empire, who reigned as the first Roman emperor from 27 BC until his death in AD 14. The reign of Augustus initiated an imperial cult and an era of imperial peace in which the Roman world was largely free of armed conflict. The Principate system of government was established during his reign and lasted until the Crisis of the Third Century.

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's mother divorced his father and married Augustus. Following the untimely deaths of Augustus's two grandsons and adopted heirs, Gaius and Lucius Caesar, Tiberius was designated Augustus's 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.