Napoleon's 1812 Russian Campaign: What Happened and Why It Failed

Start hereAt Vitebsk in late July, the daily temperature averaged 28–30 °C. On Minard's chart, it was -30 degrees Réaumur on 6 December. So was it the winter that beat Napoleon?

Napoleon invaded Russia in June 1812 with roughly 420,000 to 480,000 men, depending on who counts and what they count. By mid-December only a fraction of that army came back across the Niemen river.

Several things went wrong at once. Supply broke down in a summer of heat and long marches. The Russian armies kept falling back, avoiding the decisive battle Napoleon wanted. Moscow was emptied and burned, and the tsar would not talk peace. The retreat then ran into an unusually cold winter and disease.

This page walks through the campaign in dates, gives the numbers as ranges, and shows where the sources disagree. It ends with a simple way to read a casualty figure yourself.

011. The campaign in dates

These dates come mainly from the Fondation Napoléon, a French history charity that also publishes Napoleon’s letters.

1. 24 June 1812. Napoleon crossed the Niemen near Kovno (Kaunas, in today’s Lithuania).
2. 28 July. He reached Vitebsk and gave his tired troops a rest.
3. 16–17 August. Fighting at Smolensk; about 11,000 Russians died defending the city.
4. 7 September. The Battle of Borodino, the bloodiest battle of the campaign.
5. 15 September. He entered an almost completely deserted Moscow. Fires broke out that evening.
6. 19 October. The army left Moscow.
7. 24 October. The fight at Maloyaroslavets turned the retreat back onto the road the army had come in by.
8. 26–28 November. The crossing of the Berezina river.
9. 5 December. Napoleon left the army at Smorgon to return to Paris.
10. 13 December. What was left of the army limped back across the Niemen, the day after the Russian commander Kutuzov entered Vilna (Vilnius).

022. Why Napoleon went to war

France and Russia had been allies since the Treaty of Tilsit in 1807. By 1812 several quarrels had piled up.

• Poland. Tsar Alexander I wanted a clear declaration that Napoleon would support no independent Polish state. By July 1810 Napoleon refused outright.
• Trade with Britain. Under Napoleon’s Continental Blockade, Russia had to turn away British ships. Russia’s economy was extremely dependent on British trade, and after 1809 the blockade was enforced less strictly.
• A new Russian trade rule. On 31 December 1810 Alexander reopened Russia’s ports to goods other than British ones, and put heavy duties on goods arriving overland, mostly French.
• Oldenburg. By a decree of 22 January 1811 Napoleon seized this small German duchy. Its ruling family was tied to Alexander by marriage.
• An ultimatum. On 14 April 1812 Russia’s demand that French troops leave Prussia and Swedish Pomerania was delivered in Paris. No answer came.

What Napoleon expected is harder to pin down. On 1 June he told his wife Marie-Louise the war “will be over in three months”. Yet the Austrian minister Metternich was with him at Dresden in May. He later described Napoleon saying he would stop at Smolensk and Minsk, with his headquarters at Vilna for the winter.

And at Vitebsk he told Murat, Berthier and Eugène that the war with Russia was “a three-year war”. Our reading: his plans shifted as the Russians kept retreating.

033. How big was the army?

There is no single number, because sources count different things.

Figure	What it counts	Who gives it
422,000	The main army crossing at Kowno, as one band on a chart	Charles Minard’s chart, 1869
nearly 440,000	Men lined up along the Niemen in June	Historian Marie-Pierre Rey, 2012
about 455,000	The first invasion force, in three groups spread over 650 km	Fondation Napoléon, citing historian Thierry Lentz
480,000, with another 120,000 in reserve	Invasion force, plus reserves	Fondation Napoléon, timeline for young readers
615,000	All men committed to the whole campaign	World History Encyclopedia

Some figures count only the men who crossed in June. Others add reserves and later reinforcements. So a fair summary is roughly 420,000 to 480,000 in the first crossing, and about 600,000 counting the reserves.

Across the river, the Russian front line facing them numbered about 280,000, by the Fondation’s count. World History Encyclopedia gives around 250,000 men in the western provinces. Rey describes a multinational force combining “men from twenty different nations”, with troops from Italy, Austria, Bavaria, Prussia and the Duchy of Warsaw among them.

044. Summer: heat, hunger and a shrinking army

The army was shrinking long before the snow. Supply was the first problem. On 2 July Napoleon complained that the general staff was organised so that “nothing has been planned”.

With too little food and fodder, foraging soldiers strayed far from their units. Many were lost to ambushes and Cossack attacks. On 3 September he wrote: “we continue to lose many men every day due to the lack of order in the way in which supplies are obtained”.

The weather was hot, not cold. At Vitebsk the daily temperature averaged 28–30 °C, and the troops could not keep up any serious pursuit.

Minard’s chart shows the cost. His band for the main army starts at 422,000 at Kowno. It reads 175,000 near Vitebsk, 145,000 near Smolensk and 100,000 at Moscow.

Some of that fall is corps sent off on side routes, which he draws as thinner bands leaving the main one.

Partly Winter destroyed the Grande Armée. The cold did terrible damage on the way back. But on Minard’s numbers, most of the main army was already gone before the frosts came. His temperature line only starts with the retreat.

055. Borodino: costly and not decisive

On 7 September the two armies met at Borodino, about 124 km from Moscow. The battle lasted about ten hours. General Lariboisière estimated that all 587 French guns fired about 60,000 times.

The losses are given as ranges:

• Russians: about 45,000 dead, wounded or missing, in both Fondation accounts.
• French: between 28,000 and 35,000 in the Fondation’s 1812 timeline, or 25,000 to 28,000 in the estimate Rey reports.

Napoleon’s own count was very different. Two days after the battle he wrote: “there are 2,000 French and 12,000 Russian, and that is no exaggeration”. Rey puts the real ratio at one to two at the very most.

Partly Borodino was a clear French victory. The French held the field, but it was not the decisive win Napoleon wanted. The Russian army retreated towards Moscow. The Fondation’s timeline for young readers says neither Napoleon nor Kutuzov emerged victorious. Kutuzov described the battle to Alexander as a Russian victory.

066. Moscow and the fire: who burned it?

On 13 September, at a council of war at Fili, Kutuzov ordered the retreat, giving up Moscow. That night the city’s governor, Fyodor Rostopchin, also evacuated the 2,000-odd members of the fire brigade and nearly one hundred water pumps.

Napoleon entered on 15 September. The two Fondation timelines give different figures for who was left. One says about 262,000 people lived there in 1812, and only 10,000 remained. The other gives 200,000 inhabitants, with only 2% remaining.

The first fires broke out that evening. The next day the blaze forced Napoleon out of the Kremlin. Rain put the fire out on 20 September. A third of Moscow’s houses were utterly destroyed, and only 122 of 329 churches remained standing.

Doesn't hold up Napoleon ordered Moscow burned. The Fondation says no orders for such an act were given by Napoleon or Alexander. At the time, it was said in Russia that the French were to blame, to stir patriotic feeling.

Still argued Rostopchin had Moscow burned. This is the main suspect, but the sources do not agree.

• Rostopchin did it. Napoleon wrote to Alexander on 20 September that “Rostopchin has had it burnt down”. Rey and the Fondation’s retreat timeline also put it on Rostopchin.
• The witnesses. The French general Philippe-Paul de Ségur took part in the campaign and dedicated his history to its veterans. In the 1820s he wrote that Russian and French witnesses “all, without exception” credited Rostopchin with it. He praised it as a patriotic sacrifice, and he knew of Rostopchin’s denial but kept his view.
• His own house. Ségur also describes Rostopchin setting fire to his own country house as the French approached.
• Rostopchin denied it. In a pamphlet of 1823, he wrote that the fire had never been organised or prepared. He did not deny removing the fire pumps.
• His reasons. He wrote that he sent away 2,100 firemen and 96 pumps the day before the French entered. He would not leave the pump service in Napoleon’s hands, he said, having withdrawn every civil and military authority from the city. He suggested that vagrants among the people left in Moscow may have spread the fires in order to loot. And he said Napoleon’s bulletins named him to shift the blame.
• It is uncertain. One Fondation timeline says “What followed remains uncertain”. It lists Rostopchin’s orders, Russian scorched-earth policy and looting on both sides as possible causes.

Our reading: the evidence leans towards fires set on Rostopchin’s side. The removed pumps and the witness accounts point that way, though Rostopchin gave his own reason for the pumps, and he published this denial ten years later, in 1823.

And Napoleon, who blamed him, was an interested party, as Rostopchin pointed out. But the Fondation’s own pages differ on how sure to be, and looting may have started other fires.

077. Waiting for peace, then leaving

Napoleon expected Alexander to negotiate. He sent messages through several go-betweens, and Alexander had already stated he would not negotiate while a single French soldier was left in Russia.

On 14 October Napoleon decided to leave Moscow. As the army left, Marshal Mortier set explosives around the Kremlin, carrying out Napoleon’s orders to destroy it. Light rain and some Muscovites stopped some of the fuses, but large parts of it were destroyed.

At Maloyaroslavets on 24 October each side lost about 7,000 men. The Russians blocked the road to Kaluga. So the army turned back along the same road it had used to enter Russia.

088. The retreat, the Berezina and the cold

The winter’s first significant snowfall came on 3 November. The horses had no shoes for ice, and the men were not equipped for the cold.

Rey notes that a clothing order of 13 July listed shoes, coats and trousers but no warm clothing for a Russian winter. On 18 November Napoleon wrote that the freezing cold had killed nearly all the horses, almost 30,000 of them. He added that they had been forced to burn more than 300 artillery pieces.

At the Berezina, 50,000 men crossed near the village of Studienka on 27 November. The crossing cost between 25,000 and 40,000 men and most of the baggage. The same Fondation timeline also calls it one of his most brilliant victories, because the army did get across.

Doesn't hold up Napoleon stayed with his army to the end. On 5 December he left the army at Smorgon. News of a failed coup in Paris had shaken him. He told the diplomat Caulaincourt he could “command in Europe only from the Tuileries palace”.

He covered some 2,500 km in thirteen days and reached the Tuileries palace around midnight on the night of 18–19 December.

The men he left reached Vilna, where there is evidence that thousands had died of typhus, and the hospital was overflowing with the dead and dying.

099. How many came back?

Counts differ even more at the end than at the start.

Figure	What it counts	Who gives it
10,000	The black band back at Kowno, after 6,000 men of a side corps rejoin the main column’s 4,000	Minard’s chart, 1869
20,000	Soldiers who returned to France alive	Fondation Napoléon, timeline for young readers
about sixty thousand	Troops recrossing the Niemen	Marie-Pierre Rey, 2012
fewer than 100,000 of 615,000	Men who returned from Russia	World History Encyclopedia

Part of the gap is what “came back” means: back to the river, or back to France. Another part is who is counted: the main column, or every corps.

And not everyone missing was dead. In 2018 historian Thierry Lentz cited a study, recent at the time, showing that tens of thousands of French deserters settled in Russia. He gives the number only with question marks.

Rey writes that the campaign foreshadowed a reversal in the empire’s fortunes. She notes that Alexander led the victorious coalition forces into Paris in March 1814. Our page on the Napoleon “There is nothing we can do” meme follows the fall from Russia to St Helena.

1010. What killed the soldiers? The DNA studies

Two DNA studies have tested remains of Napoleon’s soldiers buried in Vilnius. They found different diseases.

• 2006. A team tested dental pulp from 35 soldiers in a mass grave. It found DNA of the trench fever bacterium in 7 soldiers, and of the typhus bacterium in 3 others. It also found trench fever DNA in 3 of 5 body lice from the grave. The authors concluded that louse-borne diseases affected nearly one-third of Napoleon’s soldiers buried in Vilnius.
• 2025. A team at the Institut Pasteur tested the teeth of 13 soldiers. It found the bacteria behind paratyphoid fever in four of them and relapsing fever in two. It was not able to detect the typhus or trench fever agents. The authors say these diseases could have contributed to the devastation of the army during the retreat.

Still argued Typhus destroyed Napoleon’s army. Disease was one cause among several, but which diseases did the most harm is still being worked out. The Institut Pasteur says their precise role in the deaths is not known. Its 13 samples came from more than 3,000 bodies in Vilnius.

Our reading: the two studies need not conflict, and the Institut Pasteur presents the new finding alongside the earlier one, not against it. The 2006 team used PCR tests and the 2025 team used newer genome sequencing.

The Institut Pasteur’s release notes that pathogen DNA in most ancient remains is extremely fragmented and scarce, which makes whole genomes very difficult to obtain.

Both samples are small and come from Vilnius, near the end of the retreat. So they show what some soldiers carried, not what killed the army as a whole.

1111. Minard’s chart: the campaign in one picture

Charles Joseph Minard, a retired inspector general of bridges and roads, dated his chart Paris, 20 November 1869. The copy we read is held by the library of the École nationale des ponts et chaussées.

Here is how to read it:

• The width of the band is the size of the army, one millimetre for every 10,000 men. The numbers are also written across the band.
• The colours show direction: the red band is men going into Russia, and the black band is men coming out.
• The bottom strip is a temperature line for the retreat, in degrees Réaumur below zero. It reads zero on 18 October, -21 on 14 November and -30 on 6 December. On the Celsius scale, -30 °R is about -37.5 °C.

Minard names his sources on the chart: the histories of Thiers, Ségur, Fezensac and Chambray, and the unpublished journal of Jacob, an army pharmacist.

He also says he drew the corps of Prince Jérôme and Marshal Davout as if they had always marched with the main army. Our reading: the chart redraws other writers’ figures; it is not a fresh count.

1212. How to read a casualty figure

1812 is a good place to practise, because every number comes in several versions. Before you repeat a figure, ask three questions.

1. What does it count? Dead only, or dead, wounded, missing and captured? The first crossing, or every man sent in?
2. From when to when? Back to the Niemen and back to France are different finishing lines.
3. Who counted, and why? Napoleon’s letters played down his own losses. Minard drew mostly from published histories. Some modern historians work from the army’s own registers.

Then look at timing, not just the total. A loss that happened in the summer heat needs a different explanation from one in the December cold. For more traps like these, see our guide to numbers that mislead. For Napoleon’s whole life, see our page of Napoleon Bonaparte facts.

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How we checked this · Last checked October 2026

• We read the Fondation Napoléon's three 1812 timelines, its timeline for young readers, and Marie-Pierre Rey's preface to Napoleon's letters of 1812.
• We read Minard's 1869 chart in a browser, from the copy held by the École nationale des ponts et chaussées. The Celsius conversion of his temperatures is ours.
• For the fire we read Ségur's history in its English edition of 1825, and Rostopchin's own pamphlet of 1823 in its scanned French text.
• For disease we read the abstracts of the 2006 and 2025 papers and the Institut Pasteur's press release. Neither paper shows a correction or retraction.
• We left out a claim that Russia declared war on 8 April 1812, because we could not confirm it.

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16Sources