Perhaps this weekend, when considering the mutiny of Yevgeny Prigozhin’s Wagner group, his mind will have turned briefly towards a seemingly obvious Roman parallel: Julius Caesar’s crossing of the Rubicon and marching of his troops into Italy.

Here were two leaders - crucially of private armies fiercely loyal to them personally rather than to the state - taking the remarkable step of ordering their soldiers towards their own empire’s capital. And, just as “crossing the Rubicon” has become a metaphor for taking an irrevocable step, Prigozhin’s act, however abortive the mutiny appears to have been in itself, will have irreversibly altered his own fate. It may yet, too, have serious consequences for the war in Ukraine and for Vladimir Putin’s leadership.

What did crossing the Rubicon actually mean? In 49BC, Caesar was the governor of the two provinces of Gaul, which encompassed northern Italy, France and chunks of the Low Countries. As such, he held “imperium” - that is, the constitutional power to lead troops - only within those provinces. He had no authority to cross the border, marked by the River Rubicon, from Cisalpine Gaul into Italy proper with an army at his back. Doing so was an act of treason and civil war. He wasn’t the first to do it - Sulla had led his army into Rome in 88BC. The difference was, as the classicist Mary Beard put it in her book SPQR, that “when Sulla turned his army on the city all but one of his senior officers had refused to follow him. When Caesar did the same all but one stayed with him.” That kind of absolute loyalty feels akin to the cult of personality that has, at least up to now, surrounded Prigozhin.

There are other parallels. For example, the initial lack of resistance: Prigozhin took Rostov-on-Don with the same kind of ease with which Caesar took Rimini. And there is the backdrop: Caesar, in 49BC, had been fighting in Gaul with a savagery condemned even by fellow Romans. Pliny the Elder, writing the following century, foreshadowed the modern concept of “crimes against humanity” when he said Caesar’s killings in Gaul made him guilty of “humani generis iniuriam”, a crime against the human race. “It was genocide,” says Beard, unhesitatingly, of Caesar’s murderous activities in Gaul. The Wagner group, too, is notorious for its brutality, Many in Ukraine argue that its aggression - and that of the Russian armed forces in general - is genocidal.

We might pause there before getting carried away: aside from anything, of course, any comparison with Caesar is wildly over-flattering to Prigozhin. Building up a successful catering business before engaging in grubby conflicts in Africa and Syria and taking Bakhmut is hardly the same as conquering most of France and even touching, for a moment, the exotic shores of distant Britain.

Nevertheless, even the differences between the two scenarios are instructive. In 49BC Rome, all armies were private. There was no state military, nothing like the million-strong armed forces of the Russian Federation. “Call no man rich unless he can supply a private army,” the Roman plutocrat Licinius Crassus is supposed to have said. The concentration of military power in the late republic into the hands of a small group of aristocrats, wildly enriched by the spoils of empire, was unsustainable in the face of Rome’s rapid growth. Civil war was the outcome in the short term, and in the medium term it led to a change of political system away from a quasi-democracy into an autocracy under Caesar’s adoptive son Octavian, later Augustus.

Putin is in fact much more the heir of that autocratic era than of the republican Rome into which Caesar was born. He is a post-Soviet tsar, or czar, a word itself derived from “Caesar”. Furthermore, he is a late-period Caesar: ruler of an empire that, since 1917, has been gradually breaking up, rather than, like Caesar, leader of a rapidly expanding one.

Allowing Prigozhin latitude to grow and control the Wagner group clearly worked for Putin for a time - having an arm’s-length army offered him some degree of “plausible deniability” when it came to the group’s dubious actions on and off the battlefield. But there are inherent risks of instability and violence when you allow powerful individuals to run private military forces, as became clear in late republican Rome. The emperor Augustus eventually solved this through nationalising all those personal armies - at a cost. “He gave the soldiers a fixed term of service and a pension, but it was impossibly expensive: he spent 50% of the empire’s revenue on the army,” explains Beard. That financial burden brought its own problems, just as the cost of war is weighing on Russia.

Putin is doing broadly the same thing by attempting to absorb the Wagner group into the main Russian armed forces. The deadline for the mercenary soldiers to sign contracts with the army of the Russian Federation is 1 July. Prigozhin, of course, wasn’t so keen. In an audio message put out on Monday, he said part of his aim had been to prevent “the destruction of the Wagner private military company”. His mutiny may turn out to have been his one last throw of the dice before the deadline robbed him of his personal military power.

It was Caesar who, according to his Roman biographer Suetonius, said “iacta alea est” - the die is cast - on the banks of the Rubicon. That’s the famous version of the quote. But Plutarch (one of the Ukrainian general Syrskyi’s favourite writers) insisted he said the words slightly differently, and in Greek: he quoted a line from the playwright Menander that literally means “let the dice be thrown”. There’s quite a difference: Beard, in SPQR, wonders whether the force of them was really “let’s throw the dice in the air and see where they will fall”.

Perhaps, in the end, Prigozhin’s aim wasn’t so different. His parting words through the window of the SUV in which he was driven away from the military HQ in Rostov-on-Don were: “We have shaken everyone up.”