Raising a new army for the 1813 campaign was one of Napoleon’s greatest administrative achievements. His ultimate goal was 700,000 men, including the 200,000 still fighting in Spain. In October 1812 he had sent cadres for new regiments back from Moscow to France where the conscripts of 1813 were already training. These, together with recalled veterans, 16,000 men from Spain, embodied units of the National Guard, drafts of sailors and naval gunners, made up a force of over 120,000 men, supplemented by the 1814 conscripts called in February 1813. Loyal for the moment despite the losses incurred in Russia, the Confederation of the Rhine began to rebuild its forces, and Prince Poniatowski and 10,000 faithful Poles were ready for action. In April the emperor moved east to join the 50,000 troops under Eugene still holding the fortresses of the Saale and Elbe Rivers. By the middle of the month he had assembled 226,000 men and 457 guns, with 120,000 men under his personal command. The buildup completed in August, Napoleon had over 400,000 men, including 88,000 in foreign contingents.

The quality of this vast mass was indifferent. The French infantry; young and inexperienced, was enthusiastic, but lacked training and stamina; the cavalry was inferior to that lost in Russia, its mounts poor and its troopers inexperienced. Deficiencies in cavalry and uninspired leadership – even the marshals were tired of war – gravely affected operational efficiency: But his opponents were still weak in numbers, perhaps 110,000 Russians and Prussians. Kutuzov was nominated supreme commander but died in April, and Tsar Alexander I, as ever convinced of his military talents, arrived in Germany: For the time being, the Prussians were mainly under Blucher, the Russians under Wittgenstein.

Napoleon had envisaged a rapid sweep through Prussia to relieve besieged Danzig, but modified this plan. While forces under Eugene moved to link up, Napoleon’s Army of the Main entered Saxony and on 2 May defeated the Prusso-Russians at Grossgorschen. Lacking adequate reconnaissance capability, Ney and Marmont, 45,000 strong initially, faced 75,000, but Napoleon had reinforced his numbers to 110,000 by late afternoon and steadied Ney’s wavering divisions. At about 6 p.m., with Tsar Alexander hesitating to commit is Guard, Napoleon established a grand battery of 70 guns to pound the enemy, then sent the Young Guard followed by the Old Guard into the breach. The enemy collapsed. Again Napoleon had demonstrated his ability to pin superior numbers, reinforce the decisive point and counter-attack. His weakness in cavalry, a major factor in the allied decision to attack, prevented all-out pursuit and the enemy retired in good order towards Dresden.

Napoleon, having rapidly combined his forces into one army, advanced on Bautzen, 52 kilometres north-east of Dresden, where Wittgenstein, reinforced to 96,000 men and 450 guns, had taken up a strong position. Napoleon followed with 115,000 and 150 guns, detaching Ney with 85,000 to demonstrate towards Berlin, hoping to draw the Prussians north to defend their capital. Failing this, Napoleon intended to pin the enemy by a frontal attack on 20 May; while the next day Ney would execute a manoeuvre sur les derrieres to deliver the decisive blow. Then, and later, Ney lacked the skill needed to handle a major independent command. On 21 May he committed tactical blunders that allowed the Allies to escape, the French again unable to pursue effectively: Napoleon’s plan had been excellent but the execution flawed. With some 20,000 casualties on each side the results were inconclusive.

Wittgenstein, blamed for the setback, actually the fault of Alexander’s amateurish interference, resigned command and was replaced by Barclay, who believed that the Allies would have to fall back into Poland, an option Blucher and Gneisenau opposed. In the end they agreed to retreat to positions south-west of Berlin, shielding the capital and Silesia. Napoleon entered Dresden; Davout occupied Hamburg. At this point both sides needed a rest and, on 4 June, Napoleon accepted an allied armistice proposal, eventually extended until 17 August. During this period diplomatic negotiations continued, but had little substance. Both sides reorganized and reinforced, but the Allies had more to gain than Napoleon. With England a generous paymaster, more states joined the Allies. On 3 March Bernadotte, since 1810 Crown Prince and effective ruler of Sweden, formerly a marshal conspicuous for his absence from battles, concluded an alliance with Britain. Two months later advance elements of his army landed in Pomerania. The Swedish troops were welcome, but the decisive event was Austria’s accession to the coalition.

In Vienna Napoleon’s Russian disaster created pressure for immediate war, but Metternich had no intention of unleashing popular emotions, fearing that premature action would only result in replacing French with Russian hegemony in Germany. He maintained the guise of neutrality, negotiating with both sides while authorizing covert, later overt, mobilization. By the end of Mayan Austrian army under Schwarzenberg, with Major General Radetzky as his chief of staff, had assembled. On 14 June Metternich authorized full mobilization, calling up reservists and the Landwehr. Despite severe shortages in arms and equipment, by August a very considerable army, almost 200,000 men, was concentrated in Bohemia. In addition, the Army of Inner Austria mustered about 37,000 and there were another 39,000 along the Danube. Making further efforts, by the end of August, Austria had 479,000 men under arms, with 298,000 combatants.

On 26 June Metternich met with Napoleon and delivered unacceptable terms. When, as expected, these were rejected, Austria joined Prussia, Russia and Sweden the following day. In round numbers the coalition had 800,000 against Napoleon’s 600,000, which, excluding minor theatres of operations, garrisons and rear echelons, came to 570,000 against 410,000. With Austria providing the largest contingent, Metternich insisted on naming the supreme commander. His choice was Schwarzenberg, not because of his military talents but because his aristocratic background and diplomatic experience were ideal for coping with the problems of coalition warfare, made even more difficult because of the presence of three sovereigns at headquarters.