14–68: Julio-Claudian Dynasty
Augustus had three grandsons by his daughter Julia the Elder: Gaius Caesar, Lucius Caesar and Agrippa Postumus. None of the three lived long enough to succeed him. He therefore was succeeded by his stepson Tiberius. Tiberius was the son of Livia, the third wife of Octavian, by her first marriage to Tiberius Nero. Augustus was a scion of the gens Julia (the Julian family), one of the most ancient patrician clans of Rome, while Tiberius was a scion of the gens Claudia, only slightly less ancient than the Julians. Their three immediate successors were all descended both from the gens Claudia, through Tiberius' brother Nero Claudius Drusus, and from gens Julia, either through Julia the Elder, Augustus' daughter from his first marriage (Caligula and Nero), or through Augustus' sister Octavia Minor (Claudius). Historians thus refer to their dynasty as "Julio-Claudian".
Read more about this topic: History Of The Roman Empire