In 60 B.C, rising politician Julius Caesar (centre) reconciled rival strongmen Pompey (left) and Crassus (right) and the three formed an informal alliance known as the `First Triumvirate’. It was agreed that after serving as consul in 59, Caesar should become governor of Ilyricum (former Yugoslavia), and of Cisalpine and Transalpine Gaul (the Po valley in northern Italy and southern France)

In August 55 B.C., Julius Caesar, who was fighting to establish Roman control over all of what is now France, Belgium and the western edge of Germany, invaded Britain but he withdrew shortly afterwards. He invaded again in 54 and reached the Thames before once more returning to Gaul.

Relations between Caesar and Pompey deteriorated after Caesar’s daughter, who Pompey had married, died in 54 B.C. and the third triumvir, Crassus, was killed at Carrhae the following year in an ill-judged attack on the Parthians, an Iranian people who controlled the territory east of the Roman province of Syria.

Caesar wanted to be allowed to stand as a candidate for a second consulship whilst still retaining command in Gaul as he was afraid that if he returned to Rome as a private citizen he would be prosecuted by his political enemies. In January 49 B.C, when no compromise could be reached with the senate, with which Pompey was now collaborating, Caesar led his troops across the Rubicon, the small river separating Cisalpine Gaul and Italy, to begin another civil war. The expression `crossing the Rubicon’ now means `taking an irrevocable step’

After defeating Pompey and his allies at Pharsalus in Greece (48 B.C.), and victories over other opponents in Egypt, Asia Minor, North Africa and Spain, Caesar returned to Rome where he was appointed `dictator perpetuus’ (supreme ruler for life). His measures included reform of the calendar with the introduction of leap years and the month Quintilis was subsequently renamed `Iulius’ (July) after him. In 44 B.C. he was assassinated by a group of senators who wished to restore the republican system.

After the assassination, his lieutenant Marcus Antonius (Mark Antony) pretended to be willing to co-operate with Brutus, Cassius and the other conspirators but then in his speech at Caesar’s funeral incited the crowd to turn against them. Antony then combined with Lepidus, another former lieutenant of Caesar’s, and with Caesar’s nephew, Octavian, to form the Second Triumvirate and fight a renewed civil war against Brutus and Cassius’s forces.

Since many of the conspirators against Caesar had been former Republicans pardoned by him, Antony and Octavian were ruthless against their own opponents, ordering the killing of many of them, including the leading lawyer and politician Cicero.

The decisive battle was fought in Greece, at Philippi (42 B.C.), where Brutus (shown here) and Cassius committed suicide after the defeat of their forces. The struggle is dramatised in Shakespeare’s Julius Caesar; although Caesar’s death occurs early in the play, his ghost dominates subsequent events.

The victors soon fell out and there was a renewed battle for supremacy between Octavian and Marcus Antonius, who, like Julius Caesar before him, had become the lover as well as political ally of Cleopatra, the Greek queen of Egypt.

Once again the destiny of Rome was decided by a battle in Greece. After Octavian’s victory in the naval battle of Actium, which his propaganda presented as a struggle between West and East rather than the final engagement in Rome’s civil wars, he edged Lepidus out of power to emerge in sole command of the roman state..