Caesar's heir: 44 - 37 BC

Gaius Octavius, known to history first as Octavian and then as Augustus Caesar, is born in 63 BC in a relatively obscure patrician family. His only evident advantage in life is that his grandmother is Julia, sister of Julius caesar. His great-uncle sees talent in the boy and encourages him.

Octavian is an 18-year-old student at Apollonia (in what is now Albania) when news comes in 44 BC that his uncle has been assassinated in Rome. Soon there is further information. In his will Caesar has named Octavian as his successor and has left him three quarters of his estate.

Octavian moves decisively. Hurrying back to Rome, he pays for games in honour of Caesar and raises a force of 3000 men from his uncle's veterans. But among the supporters of Caesar he has a natural opponent - Mark antony, the dictator's trusted lieutenant, who did more than anyone to calm the situation after the Ides of march.

The armies of the two men meet near Modena in 43. A victory for the young and inexperienced Octavian gives him the prestige to negotiate on equal terms with Antony. They form an alliance against the enemies of Caesar. In 42 they cross the Adriatic together in pursuit of his assassins.

The armies of Octavian and Mark antony, supporters of the murdered Caesar, and of Brutus and Cassius, his assassins, meet in 42 BC at Philippi. In two separate engagements the forces of Brutus and Cassius fare the worse. Both men commit suicide.

The two victors separate to secure control of the empire. Octavian busies himself with the western territories, while Antony moves east - into regions which he will find increasingly seductive, in the arms of Cleopatra.

Signs of tension between Octavian and Antony are eased in 40 BC when Antony returns briefly to Italy and marries Octavian's sister, Octavia. But family relations are not improved three years later when news comes that Antony, back with his army in the east, has also married Cleopatra, the queen of Egypt.

The marriage is not legal in Roman law, for Cleopatra is not a Roman citizen. But it signals the end of any pretence of alliance between the two rivals for power.

Actium and after: 31-27 BC

The Battle of Actium, in 31, decides the issue. Octavian wins. Antony and Cleopatra flee back to Egypt, where Octavian pursues them. On his arrival, in 30, they both commit suicide. Octavian stays in the east long enough to secure Cleopatra's Egypt as a new province of the empire.

In August 29 Octavian enters Rome in triumph, the undisputed master of both east and west.

The example of Julius Caesar's end makes Octavian cautious in pursuit of supreme power. During the years after his victorious return to Rome he seems to sidle, sometimes almost reluctantly, into the role which he will fill with such skill - that of emperor.

A turning point comes in the year 27 BC, when he voluntarily gives up all his military powers and is then granted by the senate a 10-year-command over three important outposts of empire - Spain, Gaul and Syria. Meanwhile he holds various civilian offices which provide him with political power at the centre.

The Roman empire: 27 BC - AD 14

It is typical of Octavian's political skill that under this arrangement the much-cherished republic of Rome appears still to be intact. Yet with hindsight historians have judged 27 BC to be the founding year of the empire.

In this same year the senate gives Octavian the life-long title of Augustus, the name by which he is subsequently known to history.

The rule of Augustus Caesar brings an unprecedented forty years of peace in Italy. With few setbacks on distant frontiers, Rome and its territories enjoy a steady increase in prosperity and trade.

The frontiers of empire are slightly extended. More important, they become stablized and properly defended. Professional careers are now possible in the army (recruits sign on for sixteen years, later increased to twenty) and in the civil service. Improved roads make it easier to keep in close touch with distant parts of the Roman world, and to move troops wherever they are needed. New towns, built to Roman design, are established in areas where there was previously no administrative structure.

The region in which Augustus makes the most effort to extend the empire is beyond the Alps into Germany. By 14 BC the German tribes are subdued up to the Danube. In the next five years Roman legions push forward to the Elbe. But this further border proves impossible to hold. In AD 9 Arminius, a German chieftain of great military skill, destroys three Roman legions in the Teutoburg Forest.

The Romans pull back (though they return briefly to avenge what seems a shameful defeat). The conclusion, bequeathed by Augustus to his successors, is that the Roman empire has some natural boundaries; to the north these are the Rhine and the Danube.

The Augustan Age: 27 BC - AD 14

The stability of Rome makes possible a flowering of the arts. The term Augustan Age will come to represent the idea of cultural excellence, just as the name of Augustus's close friend Maecenas - enthusiastic supporter of both Virgil and Horace - is now synonymous with artistic patronage. The emperor is also an enthusiastic builder. He boasts, with some justification, that he finds Rome a city of brick and leaves it a city of marble.

One of the hardest problems confronting Augustus is the question of his own Succession. His attempts to solve it are often authoritarian and blunt, but they are innocence itself compared to the connivances of his family in the five decades after his death in AD 14.