Tiberius (16 November 42 BC – 16 March 37 AD) was a Roman Emperor from 14 AD to 37 AD. Born Tiberius Claudius Nero, a Claudian, Tiberius was the son of Tiberius Claudius Nero and Livia Drusilla. His mother divorced Nero and married Octavian, later known as Augustus, in 39 BC, making him a step-son of Octavian.
Tiberius was one of Rome's greatest generals; his conquest of Pannonia, Dalmatia, Raetia, and temporarily, parts of Germania, laid the foundations for the northern frontier. But he came to be remembered as a dark, reclusive, and sombre 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 AD, he became more reclusive and aloof. In 26 AD Tiberius removed himself from Rome and left administration largely in the hands of his unscrupulous Praetorian Prefects Lucius Aelius Sejanus and Quintus Naevius Sutorius Macro.