The battle of Smolensk (16-17 August 1812) was the disappointing end to one of Napoleon's most impressive manoeuvres, an outflanking move that promised to bring him the decisive battle he desired but ended with a costly and unsuccessful attack on the walls of Smolensk.
For the first month and a half of his invasion of Russia Napoleon attempted to keep the Russian armies of Barclay de Tolly and Bagration apart and defeat them individually. His final attempt to achieve this, the manoeuvre on Vitebsk, failed in late July and on 4 August the Russian armies met up at Smolensk on the Dnieper River. Napoleon was now to their north-west, spread out between Vitebsk on the Dvina in the north and Orsha on the Dnieper in the south. He serious considered over-wintering at Vitebsk, but was eventually tempted to resume the advance east.
In early August Napoleon developed the plan for his famous manoeuvre of Smolensk. The Dnieper flows west from Smolensk to Orsha then turns south and flows towards Kiev. Napoleon decided to move his army across the Dnieper east of Orsha, then advance east along the south bank of the river. This would bring him to Smolensk while the Russians were still on the north bank of the river, and allow him to cut the roads to Moscow. The Russians would either have to offer battle on ground of Napoleon's own choice or retreat north, abandoning Moscow without a battle.
On 7 August the Russians briefly threatened to disrupt Napoleon's plans when they began a short-lived offensive between the Dnieper and the Dvina. On the following day the Cossacks won a minor victory over French cavalry at Inkovo. This alerted Napoleon to the Russian plans, and also alarmed Barclay de Tolly, who feared that it would trigger an overwhelming French attack. He stopped his advance west and instead moved north-west from Smolensk, then halted. Napoleon had cancelled his move on Smolensk, but by 10 August it was clear that the Russians were no longer a threat north of the Dnieper. The move to the Dnieper resumed, and on the night of 13-14 August General Eblé's engineers built four bridges across the river. By the morning of 14 August most of Napoleon's army had crossed to the south bank and the advance east began.
The great plan was disrupted by a single Russian division commanded by General Neverovsky. Bagration had posted this division at Krasnyi, west of Smolensk on the south bank of the Dnieper. All afternoon on 14 August Murat's cavalry threw itself at the stubborn Russians, but Neverovsky's men refused to break and instead conducted an impressive fighting withdrawal. This stopped Napoleon's cavalry reaching Smolensk late on 14 August, and also gave the Russians time to rush reinforcements into the city. By dawn on 15 August the leading troops from General Rayevsky's VII Corps entered the city from the west, where they joined Count Bennigsen's existing garrison and the survivors of Neverovsky's rearguard action.
The French largely wasted 15 August. Napoleon held a review of part of his army to celebrate his birthday, but the French missed their best chance to capture Smolensk.
In 1812 the main part of Smolensk was on the south bank of the Dnieper. The smaller New Town, or St. Petersburg suburb, was on the north bank, connected to the Old Town on the south bank by a bridge. The Old Town was protected by a four mile long medieval town wall, protected by 32 towers, an earthwork fort called the 'Royal Citadel' in the south-east and a more modern covered way and glacis. The fortifications weren't in great condition, the walls couldn't carry cannons, and there were suburbs outside the defences, so the French probably didn’t expect the city to hold out for long. Rayevsky realised that his main task was to delay the French and give Bagration and Barclay de Tolly time to reach the city and so he deployed most of his men outside the suburbs. The bulk of his infantry (23 battalions) were posted to the west and south of the Old City, with two infantry battalions and the cavalry in the east and four battalions within the city to act as a reserve. The Russians had 72 guns. 18 were massed in the Royal Citadel and the rest were spread out around the towers.
By dawn on 16 August Murat's cavalry were in contact with the Russian outposts and by 10am all of the cavalry and Ney's III Corps were in place, with Murat to the east of the Old City and Ney to the west, opposite the Krasnyi suburb. Napoleon himself still didn’t show any real sense of urgency. He spent the day to the west waiting for confirmation for news that the bridge over the Dnieper at Katan had been destroyed to protect the French left and rear against any possible Russian counterattack. He finally reached Smolensk at 1pm, and some limited fighting then began. At one point the 46th Line nearly captured the Royal Citadel when the garrison were distracted by a threatened attack towards the river bridge, but when the day ended the Russians still held most of the suburbs.
The night of 16-17 August saw reinforcements arrive on the French side, with Davout's and Poniatowski's corps both arriving. Within Smolensk Rayevsky was withdrawn to the north bank to rejoin Bagration's army and was replaced by Dokhturov's troops from Barclay de Tolly's army. Bagration was camped to the east of the town and Barclay de Tolly was approaching from the west.
The main French attack came on 17 August. This time three corps were involved, but the attacks weren't very effective. The suburbs were eventually taken but the massive medieval walls turned out to be much more effective than anyone had expected. The French artillery did massive damage to the Old Town, helping trigger a fire that destroyed most of the city, but the Russians held on to the walls.
It isn't entirely clear why Napoleon chose to launch a frontal assault on the city. The Russians were more worried by the possibility that the French were simply mask the city, move east and cut the roads between Smolensk and Moscow. This would almost certainly have been a more effective tactic than the one Napoleon chose, and this possibility was the main reason why the Russians decided to abandon Smolensk.
During the night of 17-18 August Dokhturov retreated to the New Town and destroyed the bridge over the Dnieper. At about 2am on 18 August the French realised that the Old Town had been deserted and men from I and III Corps rushed into the burning city. A force of Württembergers and Portuguese even managed to wade the Dnieper near the bridge ruins, but Bagration's rearguard was able to pin them down.
Early on 18 August most of Bagration's army began to move east to guard the Moscow road against a possible French outflanking manoeuvre. Barclay de Tolly followed late on 18 August, but Bagration had moved very quickly and a dangerous gap developed between the two armies. Luckily for the Russians Napoleon wasted another day on 18 August, and the pursuit didn't really begin until 19 August. Even then there was brief chance that the French could have won a major victory. Bagration had failed to properly guard an important crossroads at Lubino, eighteen miles to the east of Smolensk. When Napoleon realised that the Russians were heading east he sent General Junot east along the south bank of the river with orders to cross at Prudichevo and seize the crossroads. This would prevent Barclay de Tolly from escaping to the east and allow the main army to catch him. Junot did eventually get across the river, but refused to attack. This left Ney and Murat to attack the Russian rearguard at Valuntino, but the Russians held their ground and Barclay de Tolly was able to slip away to the east.
Both sides suffered heavy losses at Smolensk. The Russians lost around 12,000-14,000 men and the French 10,000-12,000. Napoleon had missed yet another chance to force the battle he desired, and just as at Vitebsk he now had to decide what to do next. He considered stopping at Smolensk or returning to Vitebsk, but eventually decided to continue with the march on Moscow. By now the Russians had decided to stand and fight, and Napoleon would get his battle at Borodino on 7 September 1812.