The conflict between France and Russia reached a boiling point when Napoleon Bonaparte declared war on Russia. Following decades of political maneuvering, the rift was exacerbated by Tsar Alexander I's withdrawal from the Continental System, which was designed to cripple Britain economically by prohibiting trade with it. Napoleon saw this as a direct challenge to his authority and a threat to the stability of Europe. To enforce his will, he mobilized an immense army, the Grande Armée, comprising around 600,000 troops from various nations under his control, intending to march into Russia and force compliance.

As the army crossed into Russian territory, Napoleon expected a quick victory. However, the vastness of the Russian landscape and the lack of local support complicated his campaign. The Russians employed a scorched-earth strategy, retreating deeper into the country while destroying crops and resources, leaving the French forces without vital supplies as they progressed. The primary confrontation occurred with the Battle of Borodino, a brutal battle that resulted in massive casualties on both sides but ultimately allowed Napoleon to capture Moscow. Despite this, the French found the city deserted and burned, leading to critical logistical issues as winter approached.

The invasion, initially regarded as a show of military strength, gradually turned disastrous as the harsh Russian winter set in. The retreat from Moscow in late 1812 became one of military history's most infamous episodes, with severe losses occurring due to the elements, starvation, and continuous Russian attacks. By the end of the campaign, the Grande Armée had been decimated, and the failed invasion marked a significant turning point in the Napoleonic Wars, leading to the eventual downfall of Napoleon.