Ancient Greek funeral pyre
© Nastasic/Getty ImagesA nineteenth century illustration depicting an ancient Greek funeral pyre.
The story of the long conflict between Sparta and Athens in the fourth century BCE is considered one of the foundational narratives of European civilisation - but it also contains multiple problems.

Prime among these, a new study argues, is the combustibility of dead soldiers.

The main source of information on the conflict is the History of the Peloponnesian War written by the Athenian historian and general Thucydides (460-400 BCE).

The book is held to be one of the fundamental texts in the development of the discipline of history - a key exercise in objective reporting, a description of cause-and-effect without resorting supernatural explanations.

As early as 1929, historian Charles Norris Cochrane called the writer the father of "scientific history".

It's a wonderful soubriquet, except, says ancient historian Owen Rees from the UK's Manchester Metropolitan University, it isn't true - at least when it comes to Thucydides' detailed, and famous, description of how the Athenians dealt with their war dead.

In a painstaking recreation of the physics and fuel loads of ancient pyres, Rees concludes that the historian's portrayal of the valiant war dead - their bodies retrieved, sorted according to membership of 10 tribes, left in state for three days, and then burned before being placed in massive communal tribal coffins and carried back to the city to be displayed before a ceremonial burial - is significantly flawed, and may indeed be dead wrong.

"Numerous questions have arisen that not only challenge our own assumptions, but also the distinct narrative given to us by Thucydides," he writes in a paper published in the Journal of Ancient History.

At issue, essentially, are the nuts and bolts of cremating large numbers of dead people - possibly stripped of clothing, unidentifiable, and rotting - in a pre-industrial war zone. According to Rees, the historian's descriptions simply don't hold water. Or, more pertinently, ash.

"If the remains of the dead were buried by tribe, does this mean that they were cremated by tribe?" he asks.

"If the remains were sent to Athens directly after battle, where were they kept in the interim period before the winter funeral? What state were the remains in, and how would this affect their semi-public display?"

Collecting the fallen after a battle cannot have been a pleasant task, but it was an important one. The Athenians held it to be a matter of honour that the dead were returned to their families.

This is demonstrated by Thucydides in his description of the battle of Solygeia in 425 BCE, when the Athenians lost fewer than 50 soldiers and were greatly perturbed because they had to leave two corpses on the battlefield.

And that, Rees points out, was a victory. What of other battles, ones that they lost, with nominated death tolls of 400, 600, or 1000?

"To exacerbate the issue further, battles with a higher loss of men commonly followed a defeat," he writes, "after which the Athenians would have had their dead returned to them naked, and possibly in a decaying state, depending on the time delay between battle and their collection."

Nevertheless, wrote Thucydides, the deceased were identified, laid in tents and honoured for two days, carefully packaged up according to affiliation, and then carried to their fiery end.

"On the day of the funeral procession coffins of cypress wood are carried out on wagons, one coffin for each tribe, with each man's bones in his own tribe's coffin," he wrote, adding later that the Athenians "took up their own dead and placed them on a pyre, then spent the night where they were".

Rees is quick to point out the obvious. If there were 10 tribes, why is there a reference to only one pyre? Were the tribes combined again in the fire? In which case, how on earth were the remains sorted again into their divisions once the flames died down? Or were the groups burned sequentially, one after the other?

Both possibilities seem absurd. In the first instance, burnt bodies are indistinguishable.

And as for burning sequentially, Rees opted for some real-world morbid research to test the proposition.

An ancient, open-air pyre, he discovered, was actually capable of reaching the 800-degree-Celsius minimum operating temperature of a modern cremator, but maintaining it for any length of time would have been impossible.

"The central area will be immensely hotter than the peripheries, while the wind and rain will affect the temperature and its distribution," he writes.

The body, or bodies, would thus burn unevenly, a situation exacerbated by dripping fat. Quite possibly, too, the weight of the corpses on top of the burning wood could, after a time, cause the pyre itself to collapse, smothering the flames and halting the process.

Using modern estimates, Rees suggests that burning a single body would require between 500 and 600 kilograms of wood.

There are no firm models for burning multiple corpses. However, an American report from 1836, after the battle of the Alamo, details the cremation of 200 dead Mexicans. The pyre stood around three metres high and had to be doused in grease to provide an accelerant.

Constantly refuelled with new wood and fresh grease, the flames of the Alamo burned for two days and two nights. Sourcing the wood alone took a platoon of soldiers a full seven hours.

As an alternative, and equally partial, model, Rees also turns to Australian government advice for incinerating cattle following an outbreak of foot and mouth disease.

"One Australian report suggests that 1.5 tonnes of dry wood is required to burn a cow," he reports, adding that the figure assumed a healthy dose of diesel had been added to help matters along.

The Australian figures, however, at least provide some sense of scale. When multiple cow corpses are burned simultaneously, the amount of wood required per animal drops to around 400 kilograms.

Armed with these numbers, Rees returns to a Thucydides example in which the Athenians used a single pyre to cremate 50 fallen soldiers.

"The 50 bodies would have required [about] 20 tonnes of wood to cremate them effectively," he writes.

"Considering that this only accounts for a single pyre, and the disposal of only 50 men," he continues, "this is a remarkable amount of a finite resource and raises an unanswerable question: where did they get all of that expendable wood from?"

It's a good question, but also one, he notes, that rests on a false assumption: that the pyres worked with modern-day efficiency and reduced the bodies to manageable and sterile piles of ash.

The Athenians should have been so lucky.

While some other sources use a Greek word meaning "ash" to describe the remains of the soldiers transported back to Athens, Thucydides chose a different term, one better translates as "bones".

Eyewitnesses to the mass burning at the Alamo reported that even after 48 hours of cremation, charred body parts were still identifiable. It is reasonable to assume, thus, that what the living soldiers carried back to their home city was not ash, but more a sort of post mortem organic muesli.

Rees estimates that on a basic body count contained in Thucydides for the whole of the war, the total remnants carried back for honour and temporary above-ground storage amounted to 19,500 litres of gunk - he prefers the neologism "cremains" - weighing around four tonnes.

Storing such large amounts of bodily ruins until interment could be arranged, Rees points out, was certainly not impossible, "but a matter of sensibilities".

"The prolonged storage of ... unburied cremains is hard to reconcile with the elaborate honours that the war dead were to be given later in the year," he notes.

And on the matter of those honours, a ceremony known as the patrios nomos, he remarks that "if these were cremains, that is partially burned remains of flesh and bone, it becomes inconceivable that the Athenians laid them out for the families to see".

All up, notes Rees, the testimony of the father of scientific history is suspect. The logistics of death, cremation and repatriation challenge the validity of Thucydides' reporting.

Of course, this comes as no surprise to classicists, who have long acknowledged that the great Greek author often presented his findings in the form of a confusing word salad.

The well-known British classical scholar Mary Beard, in one of the pieces included in her collection Confronting the Classics, makes the point that Thucydides wrote in "almost impossibly difficult Greek".

His work, she continues, "is sometimes made almost incomprehensible by neologisms, awkward abstractions, and linguistic idiosyncrasies of all kinds".

Rees agrees, although he notes that the passages describing the treatment of war dead are among the least contentious in the History of the Peloponnesian War.

"Is Thucydides creating a false image of the event?" he says to Cosmos.

"Are we just misunderstanding what he is describing? Our former models of this process are predominantly based on logical suppositions, yet some parts of it do not come from the original words of Thucydides, but from our own projections of Athenian democratic values; ancient Greek rituals for their dead; the way modern commentators want to talk about the dead; and a tendency to avoid discussing the macabre elements of this process."