Blücher was one of the leaders of the war party in Prussia in 1805, and he served as a cavalry general in the disastrous campaign of 1806. At the double Battle of Jena-Auerstedt, Blücher fought at Auerstedt, repeatedly leading the charges of the Prussian cavalry, but without success. During the retreat of the broken armies, he commanded the rearguard composed of Frederick Louis, Prince of Hohenlohe's corps. With the capitulation of the main body after the Battle of Prenzlau on 28 October, he found his march toward the north-east blocked. He led the remnant of his corps away to the north-west. Reinforcing his numbers with a division previously commanded by Karl August, Grand Duke of Saxe-Weimar, Blücher and his new chief of staff, Gerhard von Scharnhorst, reorganised his forces into two small corps totaling 21,000 men and 44 cannons. Nevertheless, he was defeated by two French corps at the Battle of Lübeck on 6 November. The next day, trapped against the Danish frontier by 40,000 French troops, he was compelled to surrender with less than 10,000 soldiers at Ratekau. Blücher insisted that clauses be written in the capitulation document that he had had to surrender due to lack of provisions and ammunition, and that his soldiers should be honoured by a French formation along the street. He was allowed to keep his sabre and to move freely, bound only by his word of honour, and was soon exchanged for future Marshal Claude Victor-Perrin, Duc de Belluno, and was actively employed in Pomerania, at Berlin, and at Königsberg until the conclusion of the war.