For over a century, there has been a popular theory that tin buttons on the coats of Napoleon’s soldiers contributed to the collapse of his Grande Armée during its disastrous retreat from Russia in 1812. The idea is that the extreme cold caused the tin buttons to transform into a brittle, crumbly form, making the soldiers' coats unusable and exposing them to the elements. However, this claim has not been confirmed by historical or scientific evidence and is widely disputed by experts. Tin, a metal used in button-making, can undergo a process called allotropism, where it changes from a stable, malleable white form to a brittle, powdery gray form when exposed to temperatures below 13.2 °C. This transformation is a slow process, taking about eighteen months to complete under prolonged cold conditions. The French army’s campaign in Russia lasted only about six months, from June to December 1812, and while they faced extreme cold—reaching as low as −39 °C during the crossing of the Berezina River—the cold was not continuous. Therefore, the transformation of tin would have been too slow to cause the widespread issues described in the legend. Archaeological studies of mass graves in Vilnius, where many soldiers of Napoleon’s army were buried, revealed that the buttons found were mostly made of brass, wood, or impure tin, not the pure tin that is vulnerable to cold. Additionally, many armies at the time used cheaper materials like bone or wood for buttons, as tin was expensive. The tin used by the French military would have been impure, making it more resistant to the cold. No survivor accounts from the time mention any issues with tin buttons, and instead describe suffering from hunger, cold, and battle injuries. The real causes behind the collapse of Napoleon’s Grande Armée were far more devastating than faulty buttons. Disease, particularly typhus, spread rapidly through the army due to lice infestations, as soldiers had not washed or changed clothes for months. Hunger and exhaustion also played major roles, as the army struggled with a lack of supplies and long marches through harsh terrain. These factors are well-documented in historical accounts and studies of mass burials from the campaign. The legend of tin buttons may have originated from a mix of true events and misunderstandings. Some researchers believe it arose from confusion between reports of tin blocks disintegrating in a customs warehouse in St. Petersburg in 1868, old Russian accounts of damaged cast buttons on military uniforms, and the overall desperate state of Napoleon’s army. When these separate stories were combined, they created a popular but inaccurate explanation for the army’s collapse.