Napoleon signed a truce with Prussia and Russia at Pläswitz on 4 June 1813. Negotiations failed to produce peace terms acceptable to both sides, and by the end of June it was clear that hostilities would resume once the armistice expired on 16 August. By then Austria and Sweden had joined the Sixth Coalition against France.
Both sides spent the brief period of peace preparing for war. The Coalition decided at Trachenberg to divide their forces into three armies, which would be positioned in an arc round Napoleon’s centre of operations in Saxony. Each would attempt to attack detached French corps, but would retreat if approached by Napoleon’s main army. The other two armies would then threaten the French flanks and lines of communication. The objective was to divide and wear the French down without fighting a major battle.
The three armies were the Army of Bohemia under the Austrian Prince Karl Philip zu Schwarzenberg, with 230,000 Austrians, Prussians and Russians; the 95,000 Prussians and Russians of the Prussian General Gebhard von Blücher’s Army of Silesia; and the Army of North Germany of 110,000 North Germans, Prussians, Russians and Swedes under Bernadotte, the Crown Prince of Sweden. A fourth, the Army of Poland, with 60,000 men under the Russian General Count Levin August Bennigsen was being formed. 
Each army contained a mixture of nationalities in order to stop Napoleon knocking one country out of the war by concentrating on it and to be sure that all acted in the interests of the Coalition.
Smaller forces took the Coalition field army to a total of 512,000 soldiers, and there were another 143,000 troops in reserve and conducting sieges and 112,000 garrisoning fortresses. It was opposed by a French field army of about 450,000, with 77,000 more in garrisons.
It is not clear who was responsible for this plan. Michael Leggiere attributes it to Count Josef Radetzky von Radetz, Schwarzenberg’s chief of the staff, but notes that several other claimed the credit.
Dominic Lieven claims that it was mainly the work of General Karl von Toll, a close adviser to the Tsar Alexander I of Russia, although he had discussed it at length with Radetzky and Schwarzenberg.
F. Loraine Petre says that the original version was the work of Toll, Bernadotte and Colonel Karl von dem Knesebeck, a close adviser to King Friedrich Wilhelm III of Prussia, with some input from others. It required only the Army of Silesia to automatically avoid a major battle. This was necessary because of its small size and Blücher’s impetuosity. Toll wanted to take the offensive against Napoleon.
Petre states that Radetzky modified it by making it require all of the armies to refuse a major battle. This, Petre argues, shows that the Austrians were still trying to conduct an 18th century war of manoeuvre rather than trying to win a decisive victory.
Schwarzenberg was the Coalition commander-in-chief, but Lieven notes that his powers were limited. He lacked confidence in his military skills, especially in comparison to Napoleon. Alexander and Friedrich Wilhelm were at his headquarters, meaning that Russian and Prussian generals, including Blücher, could go over his head and appeal to their monarch. Bernadotte, effectively a head of state because of the Swedish king’s poor health, paid little heed to Schwarzenberg.
Despite this, Lieven argues that Schwarzenberg was the best choice for the job. The C-in-C had to be Austrian, because of geography and the size of its contribution to the Coalition army. Lieven compares him to General Dwight Eisenhower in World War II in that both had the diplomatic skills to smooth over disputes between their egotistical subordinates.
Napoleon’s initial plan was to capture Berlin, which he believed would demoralise the Prussians and force the Russians to withdraw to the east and away from the Austrians. It would encourage his German allies to remain loyal, reduce the odds against him and relieve besieged French garrisons on the Oder and Vistula.
Napoleon wanted to punish both his former ally Prussia and his former subordinate Bernadotte for turning on him. Marshal Frederic-Auguste Marmont said that:
‘Passion prompted him to act quickly against Prussia. He desired the first cannon shots to be fired against Berlin, and that a startling and terrible vengeance should immediately follow the renewal of hostilities.’
Marshal Nicolas Oudinot was ordered to advance on Berlin from Saxony with 67,000 men and 216 guns. A further 37,500 men and 94 guns under Marshal Louis Nicolas Davout would march from Hamburg to Berlin. The two forces would be linked by 9,000 troops under General Jean Baptiste Girard at Magdeburg and General Jan Dombrowski’s 5,000 Poles and Wittenberg.
Napoleon ordered Oudinot to capture Berlin by 22 August. Oudinot was not an obvious choice for the job, and tried to refuse the command on the grounds of ill health, but the Emperor declined his request. Leggiere suggests that Napoleon chose him over better generals on the grounds of loyalty. David Chandler contends that Marshal Nicolas Soult was first choice, but had to be sent to Spain after the disastrous French defeat at Vitoria.
Napoleon originally intended to keep his other 300,000 men around Dresden, but he later decided to form 100,000 into the Army of the Bober under Marshal Jacques MacDonald. It was to operate in Silesia in order to prevent Blücher threatening Oudinot’s flank or Napoleon’s lines of communication.
Dresden was Napoleon’s centre of operations and main supply base. He stated that:
‘What is important to me is to avoid being cut off from Dresden and the Elbe. I will care little if I am cut off from France.’
David Chandler argues that the French had better officers and artillery. Both sides had multi-national forces, but Napoleon’s infantry, unlike that of his enemy, had homogeneous training and equipment. The main French disadvantage was the poor quality of their cavalry, which had not recovered from the huge horse casualties of the Russian Campaign of 1812.
When Napoleon his marshals of his plan Marmont objected to the division of forces into two separate groups. He told the Emperor that:
‘I greatly fear lest on the day which Your Majesty gains a great victory, and believes you have won a decisive battle, you may learn you have lost two.’
Leggiere notes that Marmont would soon be proved to be correct.
 D. Chandler, The Campaigns of Napoleon (London: Weidenfeld & Nicolson, 1966), pp. 900-1.
 F. L. Petre, Napoleon’s Last Campaign in Germany, 1813 (London: Arms and Armour Press, 1974, first published 1912), p. 170.
 M. V. Leggiere, Napoleon and Berlin: The Franco-Prussian War in North Germany, 1813 (Norman: University of Oklahoma Press, 2002), p. 126.
 D. C. B. Lieven, Russia against Napoleon: The Battle for Europe, 1807 to 1814 (London: Penguin, 2010), p. 369.
 Petre, Napoleon’s Last Campaign, pp. 181-84.
 Lieven, Russia, pp. 367-69.
 Quoted in Leggiere, Napoleon and Berlin, p. 135.
 Ibid., pp. 135-36.
 Chandler, Campaigns, p. 902.
 Petre, Napoleon’s Last Campaign, p. 189.
 Quoted in Chandler, Campaigns, p. 902.
 Ibid., p. 901.
 Quoted in Ibid., p. 903; Leggiere, Napoleon and Berlin, p. 136; and Petre, Napoleon’s Last Campaign, p. 178.
 Leggiere, Napoleon and Berlin, p. 137.