Don’t underestimate the small, Napoleon
Disease often played a decisive role in conflicts during the 18th and 19th century. Hygiene on battlefields was lacking and soldiers suffered from malnutrition more often than not. Immune systems were out of shape, rendering man and beast susceptible to disease.
Napoleon, often painted with one hand tucked in his waistcoat, was possibly scratching his hairy (?) chest rather often. He lost more soldiers to biting insects and their payloads, than in combat.
During his efforts to defeat the Turks in Syria, the plague spread among his soldiers. Most of the 2,000 French causalities had contracted the plague, with a staggering mortality rate of 92 percent of those showing symptoms.
As Haiti claimed independence, the French - ready for bloody combat - invaded the island. None of them expected their adversaries to be so small and so deadly. The mosquito Aedes aegypti is a vector for several tropic diseases, among them yellow fever that can cause a very unpretty death. Blood vessels rupture, the victims vomit black stuff that looks like coffee grounds - coagulated blood from internal hemorrhaging, and bleed from basically every orifice. After delirium and coma, death comes quickly. Haiti had mosquitoes en masse and within a year, 40,000 soldiers died of yellow fever. Only 3,000 made it back home.
A few years later, Napoleon aimed for India. To avoid Admiral Nelson’s fleet, he took his troops overland. The Grande Armeé, amassing a total of 450,000 men, rolled plundering through Poland into Russia. Their loot included typhus-infested lice. The typhus germ Rickettsia prowazekii replicates inside the lice’s gut cells, then takes the poop-express to exit the host and is smeared across small skin abrasions humans produce by excessive scratching. The Russian army kept retreating, simply waiting for the French to succumb to disease. One month into the invasion, 80,000 French soldiers died of typhus. Napoleon pushed another 300 miles towards Moscow, while his troops melted down to a mere 95,000 exhausted, starved, and lice-infested soldiers. Soon, the army was forced to retreat. Only ten percent of the Grande Armeé returned home.