Tiberius, 14-37 AD, marble, Pergamon. From the Wikipedia: Tiberius Julius Caesar Augustus, born Tiberius Claudius Nero (November 16, 42 BC – March 16, AD 37), was the second Roman Emperor, from the death of Octavian Augustus in AD 14 until his own death in 37. Tiberius was by birth a Claudian, son of Tiberius Claudius Nero and Livia Drusilla. His mother divorced his father and was remarried to Augustus in 39 BC, making him a step-son of Octavian. Tiberius would later marry Augustus' daughter Julia the Elder (from his marriage to Scribonia) and even later be adopted by Augustus, by which act he officially became a Julian, bearing the name Tiberius Julius Caesar. The subsequent emperors after Tiberius would continue this blended dynasty of both families for the next forty years; historians have named it the Julio-Claudian dynasty.
Tiberius was one of Rome's greatest generals, whose campaigns in Pannonia, Illyricum, Rhaetia and Germania laid the foundations for the northern frontier. But he came 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, the quality of his rule declined and ended in a terror. In 26, Tiberius exiled himself from Rome and left administration largely in the hands of his unscrupulous Praetorian Prefects Lucius Aelius Sejanus and Quintus Naevius Sutorius Macro. Caligula, Tiberius’ adopted grandson, succeeded the Emperor upon his death.