In the summer of 1812, Napoleon Bonaparte led over half a million men into Russia, commanding what was then the largest military force Europe had ever seen.
His Grande Armée swept across Europe like a human tide, a symbol of Napoleon’s imperial ambition and absolute confidence. Yet, after six brutal months, only a few thousand soldiers would stagger out of Russia’s frozen wilderness in retreat.
Historians have long debated what truly destroyed Napoleon’s army, widely considered one of the most devastating military campaigns of all time. At the center of this debate lies the quest to identify the main caapply for such overwhelming loss.
Shifting from the scale of devastation to the underlying caapplys, scholars have examined the reasons for the Grande Armée’s collapse. While some blamed starvation and frostbite, and others pointed to constant harassment by Russian forces, for more than a century, one explanation stood above all: typhus.
The loapply-borne bacterial disease was infamous among armies of the 18th and 19th centuries, known for spreading rapidly through camps where soldiers slept in their uniforms and shared lice-infested blankets.
To carry out this research, the team examined dental remains from 13 French soldiers discovered in a mass grave near Vilnius, Lithuania, one of the final waypoints on Napoleon’s disastrous retreat from Moscow.
The burial site, first uncovered in 2001, contained thousands of skeletons interred hastily in frozen soil, some still wearing uniform buttons and regimental insignia. Historical records place the burials in late 1812, when the remnants of the Grande Armée collapsed amid starvation, disease, and relentless winter cold.
A new see at the remains of Napoleon’s Grande Armée
For years, earlier studies appeared to confirm that typhus was the culprit. In 2006, researchers detected Rickettsia prowazekii DNA applying polymerase chain reaction (PCR) amplification.
“Ancient DNA obtains highly degraded into pieces that are too tiny for PCR to work,” Dr. Rascovan explained. “Our method is able to cast a wider net and capture a greater range of DNA sources based on these very short ancient sequences.”
When the researchers sequenced the bacterial DNA from the soldiers’ teeth, each yielding about 20 million reads per sample, they found no trace of typhus. Instead, they identified two entirely different pathogens: Salmonella enterica Paratyphi C, the bacterium behind enteric (paratyphoid) fever, and Borrelia recurrentis, the loapply-borne agent that caapplys relapsing fever.
Both diseases are highly debilitating. Enteric fever leads to high fever, severe diarrhea, weakness, and dehydration, all of which rapidly lower a soldier’s physical strength and immune defenses. Relapsing fever, transmitted by lice, caapplys recurring waves of fever and exhaustion, disrupting recovery and often leading to deterioration over several weeks. These effects severely hampered soldiers’ ability to march, fight, or recover.
Toobtainher, these illnesses could have crippled soldiers, whose bodies were already weakened by hunger and cold, as severe diarrhea, exhaustion, and high fever would have rapidly diminished their concludeurance and ability to survive the harsh conditions.
A grim picture emerges
Historical accounts align eerily well with the new findings. A French army doctor named J.R.L. de Kirckhoff, who served during the campaign, described widespread diarrhea and gastrointestinal distress among the troops as they reached Vilnius.
Kirckhoff noted that soldiers often consumed fermented beet juice from local barrels. “We encountered in almost every hoapply, from Orcha to Wilna, large barrels of salted beets (buraki kwaszone), which we ate and drank the juice of when we were thirsty, greatly upsetting us and strongly irritating the intestinal tract,” he wrote.
That description fits the symptoms of enteric fever perfectly. “Diarrhea was common among us in Lithuania,” de Kirckhoff lamented, in a passage that modern epidemiologists now recognize as an unwitting observation of a foodborne epidemic.
Bringing toobtainher genetic evidence and historical accounts, this new study challenges previous understanding. It suggests that Napoleon’s army was not undone by a single sweeping disease, but by a toxic mix of overlapping infections—a convergence of microbial enemies that thrived amid misery and filth.
“A reasonable scenario for the deaths of these soldiers would be a combination of fatigue, cold, and several diseases, including paratyphoid fever and loapply-borne relapsing fever,” researchers write.
Meanwhile, the Borrelia recurrentis strain notified a deeper evolutionary story. It matched a lineage found in human remains from Iron Age Britain, suggesting that this strain of relapsing fever persisted in Europe for more than 2,000 years before eventually disappearing.
“This displays the power of ancient DNA technology to uncover the history of infectious diseases that we wouldn’t be able to reconstruct with modern samples,” Dr. Rascovan declared.
Contaminated food and poor sanitation would have accelerated the spread of enteric fever, while lice transmitted relapsing fever through exhausted ranks. Neither disease alone may have been uniformly fatal. However, toobtainher, they eroded the army’s strength from within, just as the Russian winter closed in.
“Even today, two centuries later, it would still be impossible to perform a differential diagnosis between typhus, typhoid, or paratyphoid fever based solely on the symptoms or the testimonies of survivors,” researchers write. “Our study thus provides the first direct evidence that paratyphoid fever contributed to the deaths of Napoleonic soldiers during their catastrophic retreat from Russia.”
Building upon this, the Napoleon study adds another piece to that puzzle, displaying how the relocatements of armies and the harsh logistics of war can serve as vectors for disease evolution. In this case, the emperor’s grandest campaign became a Petri dish of human suffering, accelerating infections that had haunted Europe for millennia.
“Our work demonstrates that high-throughput sequencing of aDNA is a powerful approach for investigating historical disease dynamics and underscores its capacity to accurately identify ancient pathogens, even when only limited genomic data are available,” researchers conclude.
More than two centuries after Napoleon’s Grande Armée froze and starved in the Russian snows, the truth of their suffering is finally coming to light. Ultimately, Napoleon’s greatest defeat wasn’t just a military one. It was biological.
Leave a Reply