The French invasion of Russia, also known as the Russian campaign, the Second Polish War, and in Russia as the Patriotic War of 1812, was initiated by Napoleon with the aim of forcing the Russian Empire to comply with the continental blockade of the United Kingdom. Widely studied, Napoleon's incursion into Russia remains a focal point in military history, recognized as among the most devastating military endeavors to ever unfold. In the span of less than six months, the campaign claimed the lives of around a million soldiers and civilians.
Beginning on 24 June 1812, the initial wave of the multinational Grande Armée crossed the Neman River, marking the entry from the Duchy of Warsaw into Russia. Employing extensive forced marches, Napoleon rapidly advanced his army of nearly half a million men through Western Russia, encompassing present-day Belarus, in a bid to dismantle the disparate Russian forces led by Barclay de Tolly and Pyotr Bagration totaling approximately 180,000–220,000 soldiers at that juncture. Despite suffering enormous losses from extreme weather conditions, disease, desertion and inadequate supplies, Napoleon captured Smolensk after a two-day battle in August 1812, although the main Russian armies escaped encirclement. The Russian army continued to retreat deeper into Russia, forcing Napoleon to rely on an increasingly overstretched supply system that was incapable of sustaining such a large army in the field.
Following the Battle of Smolensk, Alexander I appointed Mikhail Kutuzov commander-in-chief of the Russian armies. The decision was widely welcomed by the army and the public, many of whom had become dissatisfied with Barclay de Tolly's continued retreats. Although Kutuzov enjoyed greater prestige than his predecessor, he largely maintained the same strategy of withdrawing deeper into Russia while preserving the army. In the fierce Battle of Borodino, located 110 kilometres (70 mi) west of Moscow, Napoleon failed to destroy the Russian army, while Kutuzov was unable to halt the French advance. At the Council at Fili, Kutuzov made the critical decision not to defend Moscow but to order a general withdrawal, prioritizing the preservation of the Russian army. On 14 September, Napoleon and his roughly 100,000-strong army took control of Moscow, only to discover it deserted and set ablaze by its military governor Fyodor Rostopchin. Remaining in Moscow for five weeks, Napoleon awaited a peace proposal that never materialized. Due to favorable weather conditions, Napoleon delayed his retreat and, hoping to secure supplies, began a different route westward than the one the army had devastated on the way there. However, after losing the Battle of Maloyaroslavets, he was compelled to retrace his initial path.
As early November arrived, snowfall and frost complicated the retreat. Shortages of food and winter attire for the soldiers and provision for the horses, combined with guerilla warfare from Russian peasants and Cossacks, resulted in significant losses. More than half of the soldiers perished from starvation, exhaustion, typhus, and the unforgiving continental climate.
During the Battle of Krasnoi, Napoleon faced a critical scarcity of cavalry and artillery due to severe snowfall and icy conditions. Employing a strategic maneuver, he deployed the Old Guard against Miloradovich, who obstructed the primary road to Krasny, effectively isolating him from the main army. Of the French commanders, Davout successfully broke through, whereas Eugene de Beauharnais and Michel Ney were forced to take a detour. Despite the consolidation of several retreating French corps with the main army, by the time he reached the Berezina river, Napoleon commanded only around 49,000 troops alongside 40,000 stragglers of little military significance. On 5 December, Napoleon departed from the army at Smorgonie in a sled and returned to Paris. Within a few days, an additional 20,000 people succumbed to the bitter cold and diseases carried by lice. Murat and Ney assumed command, pressing forward but leaving over 20,000 men in the hospitals of Vilnius. The remnants of the principal armies, disheartened, crossed the frozen Neman and the Bug.
While exact figures remain elusive due to the absence of meticulous records, estimations varied and often included exaggerated counts, overlooking auxiliary troops. Napoleon's initial force upon entering Russia exceeded 450,000 men, over 150,000 horses, approximately 25,000 wagons, and nearly 1,400 artillery pieces. However, the surviving count dwindled to 120,000 men (excluding early deserters), signifying a staggering loss of approximately 380,000 lives (dead or missing/prisoner) throughout the campaign, half from diseases. This catastrophic outcome shattered Napoleon's once-untarnished reputation of invincibility. The great loss of cavalry would particularly affect him in the subsequent campaigns. Russian losses were nearly as large, with the campaign whittling down their field army to 40,000 effectives by the time they reached the Neman River. With the considerable resources of the French Empire at his disposal (more than Russia's), Napoleon quickly went about reconstituting his army, but in this moment of opportunity Austria and Prussia switched sides to that of Russia and Britain, greatly shifting the balance of power and triggering the War of the Sixth Coalition.
The French invasion is known as the Russian campaign, the Second Polish War, the Second Polish campaign, the Patriotic War of 1812 (in Russia), or the War of 1812. It should not be confused with the Soviet term for the German invasion Operation Barbarossa during the Second World War, the Great Patriotic War (Великая Отечественная война, Velikaya Otechestvennaya Voyna). Nor should it be confused with the concurrent conflict between Great Britain and the United States, also known as the War of 1812. In Russian literature written before the Russian Revolution, the war was occasionally described as "the invasion of twelve nations" (Russian: нашествие двенадцати языков). Napoleon termed the war the "Second Polish War" to gain support from Polish nationalists and patriots. Though the stated goal of the war was the resurrection of the Polish state on the territories of the former Polish–Lithuanian Commonwealth (modern territories of Poland, Lithuania, Latvia, Belarus, and Ukraine), in fact, this issue was of no real concern to Napoleon.
From 1792 onwards, France found itself frequently embroiled in conflicts with major European powers, a direct aftermath of the French Revolution. Napoleon, rising to power in 1799 and assuming autocratic rule over France, orchestrated numerous military campaigns that led to the establishment of the First French Empire. Starting in 1803, the Napoleonic Wars served as a testament to Napoleon's military prowess. He secured victories in the War of the Third Coalition (1803–1806, leading to the dissolution of the thousand-year-old Holy Roman Empire), the War of the Fourth Coalition (1806–1807), and the War of the Fifth Coalition (1809).
In 1807, following a French triumph at Friedland, Napoleon and Alexander I of Russia signed the Treaty of Tilsit along the Neman River. These treaties progressively solidified Russia's alignment with France, allowing Napoleon to exert dominance over neighboring states. The accord rendered Russia an ally of France, leading to their adoption of the Continental System, a blockade aimed at the United Kingdom. However, the treaty imposed significant economic strain on Russia, prompting Tsar Alexander to break away from the Continental blockade on 31 December 1810. Russia at this point of history had relied on trade through the Oresund to trade with Europe but since the continental system blockaded Britain the trade route would be rendered useless. This caused the Russians to withdraw from the agreement in a neutral stance. This decision left Napoleon without his primary foreign policy tool against the United Kingdom.
The Treaty of Schönbrunn, concluding the 1809 conflict between Austria and France, included a clause that transferred Western Galicia from Austria and annexed it to the Duchy of Warsaw. This move was seen unfavorably by Russia, perceiving the territory's annexation as a potential threat for a French invasion point. Russia's Foreign Minister Nikolay Rumyantsev advocated a closer alliance with France in response.