Since Minard’s map is in French, I have provided an English language version for us to use as we discuss the flow of Napoleon’s retreat in detail. 
Napoleon’s Crossing of the Berezina 
Napoleon fought off the pursuing Russians under Prince Mikhail Kutuzov at Krasny on 17 November 1812. However, he was forced to continue to retreat to the River Berezina, leaving Orsha on 20 November.
Kutuzov had missed a number of opportunities to cut off and destroy Napoleon’s Grande Armée as it retreated from Moscow. This angered Tsar Alexander, who said that Kutuzov displayed ‘inexplicable inactivity.’
Three Russian armies were converging on Napoleon. As well as Kutuzov, Admiral Pavel Chichagov had captured Minsk, a major French supply base, and was approaching the Berezina from the south with 60,000 men. In the north, Prince Peter Wittgenstein, with 50,000 troops, had defeated Marshal Claude Victor at Smoliani.
Adam Zamoyski argues that Kutuzov realised that Napoleon and his generals and marshals were better commanders than himself and his subordinates. He consequently did not want to engage in a frontal battle with the Emperor, preferring to wait until Napoleon’s line of retreat had been cut by Chichagov and Wittgenstein.
On 22 November Napoleon learnt that Chichagov had taken Borisov and its wooden bridge across the Berezina. The next day Marshal Charles Oudinot defeated Chichagov and retook the town, but the retreating Russians burnt the bridge.
Normally the ice would have been thick enough in late November to allow the Berezina to be crossed without bridges. However, the Grande Armée, having suffered great privations from the cold, now suffered from an unexpected thaw, which caused the ice to break up.
Fortunately for Napoleon, the Russians were not pressing his army vigorously. They were also suffering from the winter, and his reputation continued to intimidate all their commanders, not just Kutuzov. He also thought that a crushing victory was not necessarily in Russia’s interests, as it would benefit Britain more. General Sir Robert Wilson, a British observer, reported that Kutuzov had said that:
I am by no means sure that the total destruction of the Emperor Napoleon and his army would be such a benefit to the world; his succession would not fall to Russia or any other continental power, but to that which already commands the sea whose domination would then be intolerable.
Napoleon considered attacking Wittgenstein, and then taking an alternative route, which would enable him to reach Vilna without crossing the Berezina. He rejected this because of the exhaustion of his troops, the poor roads and the muddy terrain, deciding to construct a pontoon bridge at Borisov.
Napoleon had ordered General Jean Baptiste Eblé, the commander of his bridging train, to destroy his equipment in order to prevent it being captured. However, Eblé had destroyed only the actual pontoon bridge, retaining his tools, smithies and charcoal. Thus, his engineers, who were mostly Dutch, could build a pontoon bridge by tearing down local houses for their wood.The problem was that the river was wide at the site of the burnt bridge, and large blocks of ice, propelled by a strong current, were floating down it. This made construction of a replacement at the same site very difficult.
General Jean Baptiste Corbineau, one of Oudinot’s cavalry brigade commanders, then reported that he had found a ford at Studienka, eight miles north of Borisov. Napoleon initially rejected Oudinot’s suggestion of crossing there, but changed his mind after meeting Corbineau on 25 November.
Eblé was ordered to start building three bridges across the Berezina at Studienka at nightfall on 25 November. Various demonstrations were planned in order to distract Chichagov, whose army was to the west of the Berezina an south of Borisov.
A detailed plan was prepared to move the troops still under discipline across the river, starting as soon as the bridges were complete. However, it depended on the enemy being distracted by the diversionary operations and no specific plans were drawn up to allow stragglers to cross.
The first bridge, intended for infantry, was completed by 1pm on 26 November, and the crossing began immediately. The second one, capable of taking wagons, was ready by 4pm. The plan to build a third was abandoned because there were not enough materials to do so.
Lack of time and materials meant that the bridges were improvised and flimsy, and continual repairs were required. The heavier one had to be closed from 8pm until 11pm on 27 November, from 2am until 4am the next morning and from 4pm to 6pm later that day. The breakages caused hundreds of death.
However, most of the organised and armed troops were across by the end of 27 November, leaving just Victor’s IX Corps as rearguard. The Gendarmes had so far prevented unarmed men and civilians from crossing, but they were now invited to cross. Many, having settled down beside camp fires and, seeing no immediate danger, decided to wait until morning.
The strength of the Grande Armée at this stage is uncertain, but David Chandler estimates that 25,000 men under arms, 110 guns and 40,000 stragglers left Orsha. Joining up with Oudinot and Victor’s corps increased its strength to perhaps 49,000 combatants, 250-300 guns and 40,000 stragglers. About 75,000 Russians were close enough to interfere with the crossing.
Chichagov was slow to realise what was happening, and did not engage Oudinot, who was covering the southern flank on the west bank of the Berezina, until the morning of 27 November. The French had to surrender ground, but maintained their line.
On the east bank of the Berezina, Victor also gave up some ground under pressure from Wittgenstein, but his corps remained intact and Napoleon left able to withdraw one of its brigades, comprised of Germans from Baden, across the river.
The action on both banks began again early on 28 November. Chichagov’s advance guard, commanded by General Eufemiusz Czaplic, a Pole, attacked Oudinot. The position looked so bad for the French that Napoleon prepared to commit the Old Guard, but Oudinot rallied his men. He was wounded, for the 22nd time in his career, and Marshal Michel Ney took command.
Ney was outnumbered by over 30,000 to 12-14,000 men, and his troops were in a worse physical condition. Three quarters of his men, which included Poles, Italians, Wüttermbergers, Dutchmen, Croats, Swiss and Portuguese as well as Frenchmen, fought gallantly.
Ney ordered General Jean-Pierre Doumerc’s cuirassier division to charge the enemy. Czaplic was wounded and 2,000 of his men were captured. This charge, described as ‘brilliant’ by Chandler, forced the Russians back. Fighting continued for the rest of the day, but the line had been stabilised.
On the east bank Victor’s force of 8,000 men, mostly from Baden, Hesse, Saxony and Poland, was attacked at 9am by Wittgenstein, who had numerical advantage of four to one. However, the morale of Victor’s men remained, according to Zamoyski, ‘unaccountably high’ and they held out.
Victor faced a crisis on his left flank because he was short of troops. One of his divisions, commanded by General Louis Partouneaux, had been ordered to withdraw from Borisov to Studienka in the early hours of 28 November. It took the wrong road and was captured.
Napoleon therefore ordered the Baden brigade that had been withdrawn the day before to cross back over the Berezina. Doing so was very difficult because of the large number of stragglers coming the other way, but the infantry managed to force their way across.
The Russians were able to bring up guns on Victor’s left, which bombarded the bridges, causing panic and great losses amongst the stragglers. Napoleon deployed guns on the west bank, and they inflicted heavy casualties on the Russians who were trying to envelop Victor’s left.
Victor and his men were ordered to retire across the river at 9pm. The bridges had first to be cleared of the dead men and horses and the wreckages of wagons. By 1am, only a small screen was left on the east bank. Victor and Eblé urged the remaining stragglers to cross, but most again decided to wait.
Victor’s last men withdrew at 6am, and the stragglers at last realised the urgency of the situation. Eblé had been ordered by Napoleon to burn the bridges at 7am, but waited until 8:30am because so many were still on the other side of the river. By then the Russians were close to the bridges, leaving him no choice to set them on fire, even though thousands had still to cross.
Chandler argues that ‘Napoleon was undoubtedly in a position to claim a strategic victory’ at the Berezina.’ He had extracted the survivors of the Grande Armée, albeit with heavy losses. Chandler attributes this to the inactivity of the Russian commanders and the efforts of Eblé, who he describes as ‘the true hero of the Berezina’, Oudinot and Victor.
Chandler also suggests that Kutuzov’s lack of urgency during this phase of the campaign is difficult to interpret as ‘anything else than a deliberate desire to allow Napoleon to escape over the Berezina’
The crossing of the Berezina marked the last major combat of Napoleon’s 1812 Campaign. He had originally intended to fight Chichagov in order to clear the route to Minsk, but the losses incurred in the crossing meant that he had no choice but to retreat to Vilna.
The crossing of the Berezina did not, however, mean the end of the Grande Armée’s ordeal. It continued to suffer casualties in rearguard actions, and to the weather; the temperature was still falling.
Next: The End of Napoleon’s 1812 Russian Campaign
 Quoted in A. Zamoyski, 1812: Napoleon’s Fatal March on Moscow (London: HarperCollins, 2004), p. 432.
 Ibid., pp. 435-7.
 Quoted in D. Chandler, The Campaigns of Napoleon (London: Weidenfeld & Nicolson, 1966), p. 834.
 Ibid., pp. 841-42.
 Zamoyski, 1812, pp. 471-73.
 Chandler, Campaigns, p. 842.
 Zamoyski, 1812, p. 473.
 Chandler, Campaigns, p. 845.
 Ibid., p. 841.
 Ibid., p. 846.
 Mike Stucka, English translation of Minard’s classic chart of Napoleon’s March, Analyticjournalism.com, November 4, 2006, http://www.analyticjournalism.com/2006/11/04/english-translation-of-minards-classic-chart-of-napoleons-march/
 Martin Gibson, Napoleon Retreats from Moscow, 18 October 1812, War and Security Blog, October 17, 2012, http://warandsecurity.com/2012/10/17/napoleon-retreats-from-moscow-18-october-1812/.