The campaigns carried out between Napoleon I and the European powers, including Britain (1796–1815). The first great Italian campaign (1796) under Napoleon I secured a series of decisive victories for the French over the Austrians in northern Italy. In 1798 he led an expedition to Egypt, but the British fleet under Admiral Nelson destroyed the French fleet in Aboukir Bay. In 1799 Napoleon I led an army over the Alps to win the Battle of Marengo (1800) over the Austrians. Britain, apprehensive of Napoleon’s threat in the Mediterranean and in continental Europe, was by 1803 once more at war with France. Nelson destroyed the combined Spanish and French fleets at Trafalgar (1805), and in the same year Napoleon swung his grande armée towards Austria, which, with Russia and Sweden, joined Britain in the Third Coalition. Napoleon’s forces encircled the Austrians at Ulm, forcing them to surrender without a battle. Napoleon fought and defeated the emperors of Austria and Russia at the Battle of Austerlitz (1805) and forced Austria to sue for peace. In the following year Prussia joined the Third Coalition but, in a campaign that lasted 23 days, Napoleon broke the Prussian armies at Jena and Auerstädt and accepted the surrender of Prussia. The Russian emperor Alexander I concluded a treaty of friendship and alliance with Napoleon at Tilsit in July 1807. In 1808 a revolt broke out in Spain, which by now was also under French rule. Napoleon sent a large force to quell it but was confronted by the British army under Sir Arthur Wellesley, later Duke of Wellington. Britain won a series of victories in the Peninsular War, which, though not conclusive, occupied 300,000 French soldiers when they were needed elsewhere. In 1812 Napoleon I defeated the Russians at Borodino and occupied Moscow, but instead of suing for peace, Alexander I’s forces withdrew further into the country. Napoleon I’s grande armée was forced to retreat from Moscow in the severest winter conditions, which cost the lives of nearly half a million men. After a crushing defeat at Leipzig the following year, Napoleon I abdicated and retired to Elba (1814). Next year he returned to France and was finally defeated by Wellington and Blücher at the Battle of Waterloo (1815).