began an affair with her, which he later continued as king. In 1809, Napoléon had Württemberg commit troops for his war against Austria, while safeguarding its own eastern borders. Frederick William received the command of the troops deployed for border defence. At Napoleon's Russian campaign, Frederick William was again in command of troops. The campaign was devastating for the Württemberg army. Of the 15,800 soldiers, only a few hundred returned to Württemberg. After the Battle of Leipzig from 16 to 19 October 1813, Württemberg moved to the side of the alliance against Napoleon. Frederick William then took over the command of the Army of Württemberg, which was reinforced by Austrian troops in November. On 30 December the army crossed the Rhine at Hüningen. Despite having suffered heavy losses in 1812 and 1813 fighting as an ally of France, Württemberg agreed to raise an army for the Allies of 12,250 regular infantry, 2,900 cavalry and 12,250 militia. By strenuous efforts this quota was filled. At first, the Württemberger contingent was designated the German VI Corps, but in a subsequent reorganization it became the IV Corps in the main Allied army of Austrian field marshal Karl Philipp, Prince of Schwarzenberg. It marched to war with 14,000 men and 24 artillery pieces. Frederick William directed his corps in the First Battle of Bar-sur-Aube on 24 January 1814. One source asserted that IV Corps suffered 900 casualties in this combat while their Austrian allies lost 837. French losses were about 1,200. The IV Corps participated in the Allied victory over Napoleon at the Battle of La Rothière on 1 February. On 18 February 1814, Schwarzenberg ordered Frederick William to hold Montereau until evening. Accordingly, the Crown Prince placed 8,500 foot soldiers, 1,000 horsemen and 26 artillery pieces on the north bank of the Seine River. The defending force included an Austrian brigade. The first French attacks in the morning were driven off, but by the mid-afternoon Napoleon was on the scene with 30,000 troops and 70 cannons. Frederick William ordered a retreat, but the movement quickly degenerated into a mad dash for safety across the single bridge with French cavalry in hot pursuit. The Allies lost 2,600 killed and wounded, plus 3,400 soldiers and 15 field pieces captured. The French lost 2,000 but captured the vital bridge intact. The Württembergers reported 806 killed and wounded, not counting prisoners. On 25 March, the main Allied