In the Ptolemaic tradition, Cleopatra marries her brother Ptolemy XIII and at the age of eighteen is joint ruler of Egypt

Julius Caesar crosses the river Rubicon (the southern boundary of Gaul) with his army – and in doing so launches a civil war

Julius Caesar defeats his rival Pompey at Pharsalus, in Greece, and makes himself master of the Roman world

Julius Caesar, now fifty-two, meets the 21-year-old Cleopatra in Alexandria and they become lovers

Cleopatra gives birth to a son and calls him Ptolemy XV Caesar (later known by the nickname Caesarion)

Octavian, an 18-year-old student in Apollonia, hears that he has been named by his uncle, Julius Caesar, as his successor and heir

Herod, appointed king of Judaea by the senate in Rome, establishes his rule over Palestine

Cleopatra commits suicide, applying a poisonous asp to her breast,

Octavian is given the life-long title of Augustus by the senate in Rome, becoming in effect the first Roman emperor

After the death of two of his grandsons, the emperor Augustus formally adopts his stepson Tiberius as his successor

Augustus Caesar insists on Tiberius adopting as his successor Germanicus, a talented young member of the imperial family

Germanicus, designated eventual heir to the throne, marries Agrippina, granddaughter of the ruling emperor

The period of stability achieved during the reign of Augustus Caesar has been given the name Pax Romana ('Roman peace')

The death of Augustus introduces half a century of chaos, as the members of his family compete ruthlessly for power

Tiberius succeeds his stepfather Augustus Caesar as the Roman emperor

Germanicus, nephew and heir of the emperor Tiberius, dies when far away with the army in Syria

The Han dynasty recovers control, after a 15-year interlude, and moves the capital to Loyang - starting the Eastern Han period

Within the tangled and tormented web of the Roman imperial family, Gaius Caesar - nicknamed Caligula - inherits the throne

Claudius, after the assassination of his nephew Caligula, is selected as emperor by the praetorian guards

Herod Agrippa, a grandson of Herod the Great, restores a brief calm to Palestine

The 16-year-old Nero is proclaimed emperor by the praetorian guards after the death of Claudius, supposedly poisoned by toadstools

A great fire in Rome is popularly believed to have been started by Nero, whom legend also accuses of fiddling while the city burns

A rebellion in Spain prompts such chaos that Rome has four emperors within a year, after the suicide of Nero in 68

Vespasian, proclaimed emperor by his troops in Alexandria, is the survivor among this year's four emperors

Titus becomes emperor on the death of his father, Vespasian, and begins a brief two-year reign of lavish public generosity