On 10 January 49 BC, when Julius Caesar and his army crossed the river Rubicon in Northern Italy and began the fateful march on Rome, he didn’t say, as is often stated, alea iacta est, ‘the die is cast’. My Oxford colleague Professor Llewelyn Morgan regularly cautions Twitter users that Caesar was in fact quoting, according to the historian Plutarch, words from a play by the Greek comic poet Menander, anerriphthô kubos  – which means ‘Let the die be cast’. The phrase was either mistranslated by the Roman historian Suetonius, or his text has been incorrectly transmitted. In Latin ‘let the die be cast’ would simply require an addtional o at the end – alea iacta esto. The difference is subtle but telling. Caesar was about to embark on a gamble, a risky adventure whose outcome could not be certain but on the success of which he was prepared to wager. He was not saying that there could be no turning back, which is how the misquoted phrase is commonly understood.

The world looked on in bafflement in June 2023 as the Wagner group leader Yevgeny Prigozhin did exactly that – turn back – after having appeared to take a similar gamble by marching on Moscow with 25,000 mercenary soldiers and a slew of blood-curdling threats. He had thrown down the gauntlet to President Putin: his public fulminations against the defence chiefs of the Russian federation and his accusations against Putin himself surely meant that there could be no happy return to Moscow’s fold under its current leadership. He would either succeed in his gamble and take over from Putin as dictator – his evident goal, according to some onlookers – or be defeated, leaving a bloody footnote in Russia’s war against Ukraine. In the event, the promised march on Moscow and the ‘military mutiny’ denounced on television by Putin himself fizzled out within 24 hours. Prigozhin appeared to have crossed the Rubicon by marching unopposed, and even publicly hailed, to Rostov-on-Don; he then promptly re-crossed it, claiming implausibly that he did not wish to shed Russian blood.

The history of ancient Rome affords more than one parallel for a march on the centre of power by a disaffected and ambitious military commander. Julius Caesar was well aware of the actions of Rome’s erstwhile dictator Lucius Cornelius Sulla some decades earlier, during Rome’s bitter civil war, in which Sulla was pitted against Gaius Marius, Rome’s then ageing but still vigorous general under whose command Sulla had once served with distinction. Sulla had played an important part in the Social War (91-87 BC), in which Roman forces had been dispatched against rebellious Italian allies; his reward was to be appointed consul in 89 BC and be given command of a Roman army in the East. However, the potentially lucrative military campaign against the king of Pontus, Mithridates, was coveted by Marius, who conspired with Sulla’s political opponent, the tribune Sulpicius Rufus, to overturn the appointment so that Marius himself might be awarded it. When riots engineered by Sulpicius broke out in Rome, Sulla as consul declared a holiday and the closure of public buildings, rather as Putin did when he announced the ‘mutiny’. This only aroused further discord; and after taking refuge, to his humiliation, in Marius’s house, Sulla was forced to flee south to the city of Nola. In his absence Sulpicius transferred the Eastern command to Marius.

Sulla appealed to his troops, who had remained loyal to him and were furious at the thought of being deprived of the chance of glory and riches in the East. With six legions (around 25,000 men) Sulla marched along the Via Appia towards the capital. In response to an embassy from the Senate inquiring his purpose, he claimed that he was freeing Rome from tyrants. The boundary of the city, within which Roman citizens were forbidden to bear arms, was marked by a furrow, the pomerium, ploughed allegedly by Romulus, the legendary founder of Rome. For an army to cross it would be to violate a sacred taboo, and some of Sulla’s officers and troops deserted him at that point, a notable exception being his lieutenant Marcus Crassus. When the Sullan troops entered the city, Marius fled Rome with his son, while Sulpicius was killed by a slave (whom Sulla later put to death for his betrayal). Conscious of his earlier humiliation at the hands of Marius, Sulla then left for the East to pursue success in war. There he remained for six years, defeating Mithridates’ forces in several battles before making a peace agreement with the king in 83 BC.

In the meantime Rome succumbed to violence. After Sulla’s departure Marius had returned and wreaked bloody vengeance on his political enemies, before he himself died in 86 BC, leaving behind a city riven with strife. In October 82 BC Sulla, buoyed up with his Eastern conquests, once again marched on Rome. After soldiers under the command of Crassus defeated the Samnite troops amassed against them at the Colline Gate, Sulla entered the city. He calmly addressed the Senate to the sound of the screams of thousands of prisoners being butchered on the Campus Martius. The cowed Senators awarded him the title of dictator for an indefinite period, and he was granted immunity for all actions past and future. A reign of terror followed, characterised by Sulla’s infamous ‘proscriptions’ – published lists of hundreds of political opponents who he ordered should be murdered on sight.

Sulla’s march on Rome and his assumption of the title of dictator offered a clear precedent to Julius Caesar in 49 BC, when he crossed the Rubicon and became Rome’s dictator. But surprisingly (and to Caesar’s derision) Sulla resigned his powers in 80 BC and retired into private life, dying two years later. The bald outline of his actions cannot do justice to the terror, the bloodshed, the personal vendettas, the slighted egos, the deadly machinations, the greed for money and power, and the countless brutalities that characterised his feuding with Marius, his battles with Mithridates, and his unforgiving cruelty to his political foes. In these aspects, at least, the parallels with what may happen in Russia following Prigozhin’s aborted march on Moscow may be imagined. The consequences have yet to be played out, but what Prigozhin has done cannot be reversed: in this case it seems fitting enough to use the phrase alea iacta est.