Does the story of the Roman Republic’s fall and Julius Caesar’s rise to power have anything to tell us about the world we inhabit today? The BBC and PBS are betting that it does. Their three-part documentary Julius Caesar: the Making of a Dictator sets out to tell this tale with just enough references to Donald Trump, Vladimir Putin and the End of History to keep the viewers’ ears pricked for contemporary resonances. Unwatched democracy gives way to populism, populism ushers in the tyrant. So constitutions fall.

The Rome we meet in this series is a society mired in crisis. The eponymous dictator is shown to be a man who, when the gods were handing out scruples, was off getting double-helpings of ambition. Each episode begins with the same introduction, delivered in the inviting if urgent tones one is used to hearing from Masterchef:

For 500 years, [Rome] was ruled by elected government… In a little over a decade, this Republic was overthrown by the ambitions of one man, [who bent] a centuries-old political system to breaking point.

The rise of Julius Caesar is shown to be a procession of Republican norms and conventions being crushed under the red leather boots Caesar took to wearing in his later years (a symbol, so say our ancient sources, of his tyrannical ambitions).

But how true a portrait is this of the Roman Republic in the 50s and 40s BC? Were these years really marked by an escalating series of crisis-inducing challenges to Rome’s political authority? Was the collapse of this system of government really brought about by one man overriding the safeguards that had protected Rome since the aristocracy expelled the kings in 509 BC? Did one man really bring about this Republic’s Götterdämmerung?

Even those disinclined to follow this interpretation must acknowledge that this is the picture painted by our ancient sources. The historians agree with the biographers who agree with contemporary writers: Julius Caesar was the decisive factor in Rome’s downfall.

Unanimity in our ancient sources, however, is as much a cause for concern as it is for confidence. The desire to follow the picture handed down by these writers and thinkers rests upon a shaky premise: that politically-motivated individuals shouting about an unprecedented crisis is proof positive that that crisis exists.

Consider the decades that preceded Caesar’s mould-shattering, crisis-inducing career. Did his short time strutting the world’s stage represent a short burst of exceptional chaos? Was it an exception to a background of politics as usual? Far from it. In the years before Caesar launched his political career, a time when he was practising law in the Forum and getting kidnapped by pirates, Rome suffered a truly extraordinary catastrophe at the hands one of her consuls. In 78 BC, a recently elected general named Marcus Aemilius Lepidus put himself at the head of a revolutionary army in Etruria and marched on Rome, seeking to overturn the most recent constitutional settlement. He was only prevented from doing so by the army commanded by his consular colleague, who smashed his forces in a battle on the outskirts of Rome. Should we believe that this is trumped by Caesar dumping a bucket of faeces over his fellow consul’s head in order to warn him off his (highly irregular) obstructionist behaviour?

Only a decade before that, another consul reacted badly to having a plum provincial command snatched from him by an ambitious rival. Lucius Cornelius Sulla took command of the troops he had been promised and marched them into the city, scattering his enemies and initiating a civil war. This crisis was concluded after much bloodshed in a meeting of the senate held outside Rome’s sacred boundary. As Sulla laid down the terms of his victory, he had his prisoners of war butchered within earshot of the gathered senate. It is not recorded whether Sulla matched Caesar’s audacity in failing to stand to greet the senators as they entered the chamber.

This exercise could be repeated for the Social War in 91 BC, an existential war against Rome’s Italian allies sparked by the murder of the tribune who was attempting to broker peace (better or worse than Caesar granting his citizen soldiers leave to vote in elections?). Or for the Jugurthine War in the second century, a minor provincial dispute blown out of all proportion by the discovery of a potentate’s bribery of the Roman political establishment (pales into comparison next to a campaign not to execute suspected terrorists without trial). Even the histories of the Punic Wars and the legends surrounding the Gallic sack and burning of the city contain tales of the disgraceful arrogance of Rome’s leaders. Caesar pushed the boundaries of acceptable conduct, but in doing so he showed himself at his most conformist.

Why, then, is Julius Caesar singled out as uniquely ambitious, unmatched in his pursuit of tyranny and personal power? The simplest answer is that this is the period for which we have sources. The extraordinary detail with which Caesar’s rise and fall can be reconstructed is thanks only to the survival of speeches, commentaries, treatises and even personal correspondence from some of this period’s biggest movers and shakers. This extraordinary cache of documents gives us eyewitness accounts of Caesar’s alliance with Pompey and Crassus, his consulship, his invasion of Italy, his dictatorship and his bloody assassination. They are replete with descriptions and predictions of catastrophe and crisis.

But what does that prove? Merely that Caesar was held to be a world-ending threat by his contemporaries. Should we really expect the vanished source material from those earlier periods to say anything different about their own bêtes noires? Are we to expect that the speeches which greeted Lepidus’ revolt were woolly-minded attempts to understand his point of view? Or that men on the run from Sulla’s assassins contented themselves with letters predicting a return to normalcy after the inevitable carnage?

The survival of texts from one period and not another is not an accident to be waved away without thought. Something about this particular crisis convinced subsequent generations to preserve its record, and it would be perverse to imagine that this interest was unrelated to the fact that these authors bore witness to the Republic’s collapse. That does not, however, prove the veracity of their doom-mongering.

Caesar’s career was not significantly more scandalous or catastrophic than those of the ambitious but more obscure generals who preceded him. He was, however, the straw that broke the camel’s back. The Roman Republic had survived those moments of crisis, why could it not recover from the civil war Caesar fought against his enemies? If the explanation is not found in a study of Caesar, then we should turn to his opponents.

The simplest explanation for the Republic’s final collapse lies not in the manner of Caesar’s victory, but in that of his opponents’ defeat. The brief civil war brought about by Caesar’s crossing of the Rubicon ought to have concluded in 48 BC with his decisive victory at Pharsalus – the bulk of his enemies’ forces defeated, their allies routed, their commander-in-chief dead. Instead, the two halves of the coalition that opposed Caesar fought on, hopelessly. The Optimates dug in in Africa, holding out for another two years. The Pompeians continued their resistance for another year after that. Cato, the figurehead of resistance to Caesar, ventriloquised in this series by Rory Stewart, did not react to his defeat at Thapsus by settling scores on a podcast. Rather, he pulled out his own guts as a final gesture of defiance to the victorious Caesar. Pompey’s sons occupied Andalusia, refusing to submit to Caesar’s authority at a cost of more than 30,000 lives.

This war was different. After Sulla had won his battles in the field, he used his dictatorship to pass laws to set the ship of state on an even keel. Once his position was secure, he returned power to the senate and the people of Rome. By the time Caesar had completed his final victory in Spain, what Republican establishment existed to take back power? The lively aristocracy of the Roman Republic lay buried across the Mediterranean. The new men who took their place in the senate had acquired their status through loyalty to their general. These were not men to be entrusted with global dominion, not yet at least. Caesar did what he had done throughout his career – he held onto power waiting for an opportunity to arise that only he would be bold enough to seize. The clock ran out on him.

What was it that had made Caesar’s opponents so uniquely keen to fight him to the death, to have the Republic buried with them rather than be entrusted to Caesar? It is not correct to say that it was because Caesar was truly an implacable and hateful tyrant from his earliest days. It was rather because his enemies had convinced themselves that this was the case. Cato’s extraordinary rise to prominence was not a result of some special insight he had into Caesar’s character. It was because he told the elite what they wanted to hear. He created an enemy for them, someone against whom they could define themselves. By revelling in his lurid denunciations of Caesar’s life and career, they could affirm their own virtue, and discern their true allies.

In the Optimate echo chamber, Julius Caesar became tyranny incarnate, a figure of out-sized, cartoonish evil, a man with whom any compromise would be a betrayal. Anyone who tried to meet Caesar halfway or sought the centre ground was castigated as a traitor and shunned from the establishment’s company.

The Optimates had made a virtue of their refusal to tolerate Caesar; opposition to his every move was fundamental to their worldview; it formed the core of the face they presented to the world. Every battle with Caesar was rendered an existential one. Every position taken by Caesar had to be opposed as a result of his having taken it. There could be no debate with tyrants.

There are numerous examples of Caesar and his allies reaching for compromise: Caesar’s consulship began with an invitation to debate his land bill, not a demand to pass it or face the consequences. It was one of Caesar’s tribunes who proposed de-escalating the civil war by having both Caesar and Pompey lay down their arms simultaneously. Once the civil war began, Caesar sent out messengers proclaiming that anybody who wished to remain neutral would come to no harm. The Optimates insisted that you were with them, or you were against them. A fight between these parties was inevitable, and that it was always going to be a fight to the death.

It was Caesar’s enemies who cast the die. And they lost.