Napoleon Bonaparte’s 1812 march on Russia was one of the most deadly campaigns of all time, with many fatalities not due to the fighting at all. How many French and allied soldiers perished in the campaign?
Answer: Some 400,000, with fewer than a quarter of them doing so in battle. Most died of disease, such as typhus and tuberculosis, or from starvation and severe cold. A similar number of Russian soldiers also perished.
Source: 1812 – Napoleon’s Fatal March on Moscow by Adam Zamoyski