War of the Third Coalition

War of the Third Coalition was a European conflict spanning 1805 to 1806. During the war, France and its client states under Napoleon I opposed an alliance, the Third Coalition, which was made up of the United Kingdom, the Austrian Empire, the Russian Empire, Naples, Sicily, and Sweden. Prussia remained neutral during the war. Britain had already been at war with France following the breakdown of the Peace of Amiens and remained the only country still at war with France after the Treaty of Pressburg. From 1803 to 1805, Britain stood under constant threat of a French invasion. The Royal Navy, however, secured mastery of the seas and decisively destroyed a Franco-Spanish fleet at the Battle of Trafalgar in October 1805. The Third Coalition itself came to full fruition in 1804–05 as Napoleon's actions in Italy and Germany (notably the arrest and execution of the Duc d'Enghien) spurred Austria and Russia into joining Britain against France. The war would be determined on the continent, and the major land operations that sealed the swift French victory involved the Ulm Campaign, a large wheeling manoeuvre by the Grande Armée lasting from late August to mid-October 1805 that captured an entire Austrian army, and the decisive French victory over a combined Austro-Russian force under Alexander I of Russia at the Battle of Austerlitz in early December. Austerlitz effectively brought the Third Coalition to an end, although later there was a small side campaign against Naples, which also resulted in a decisive French victory at the Battle of Campo Tenese. On 26 December 1805, Austria and France signed the Treaty of Pressburg, which took Austria out of both the war and the Coalition, while it reinforced the earlier treaties of Campo Formio and of Lunéville between the two powers. The treaty confirmed the Austrian cession of lands in Italy to France and in Germany to Napoleon's German allies, imposed an indemnity of 40 million francs on the defeated Habsburgs, and allowed the defeated Russian troops free passage, with their arms and equipment, through hostile territories and back to their home soil.