Tiberius (Latin: Tiberius Julius Caesar Augustus; 16 November 42 BCE – 16 March 37 CE), is Roman Emperor from 14 CE to 37 CE.

Tiberius is by birth a Claudian, son of Tiberius Claudius Nero and Livia Drusilla.

His mother divorces Nero and marries Augustus in 39 BCE, making him a step-son of Octavian.

Tiberius will later marry Augustus' daughter Julia the Elder (from his marriage to Scribonia) and even later be adopted by Augustus, by which act he officially becomes a Julian, bearing the name Tiberius Julius Caesar.

The subsequent emperors after Tiberius will continue this blended dynasty of both families for the next forty years; historians have named it the Julio-Claudian dynasty.

In relations to the other emperors of this dynasty, Tiberius is the stepson of Augustus, great-uncle of Caligula, paternal uncle of Claudius, and great-great uncle of Nero.

Tiberius is one of Rome's greatest generals, conquering Pannonia, Dalmatia, Raetia, and temporarily Germania; laying the foundations for the northern frontier, but he comes to be remembered as a dark, reclusive, and somber ruler who never really desired to be emperor; Pliny the Elder called him tristissimus hominum, "the gloomiest of men."

After the death of Tiberius’ son Drusus Julius Caesar in 23 he becomes more reclusive and aloof.

In 26, against better judgment, Tiberius exiles himself from Rome and leaves administration largely in the hands of his unscrupulous Praetorian Prefects Lucius Aelius Sejanus and Quintus Naevius Sutorius Macro.

Caligula, Tiberius' grand-nephew and adopted grandson, succeeds the emperor upon his death.