of Trafalgar on 21 October (the British commander, Lord Nelson, died in the battle). Napoleon never again had the opportunity to challenge the British at sea, nor to threaten an invasion. He again turned his attention to enemies on the Continent. In April 1805, Britain and Russia signed a treaty with the aim of removing the French from the Batavian Republic (roughly present-day Netherlands) and the Swiss Confederation. Austria joined the alliance after the annexation of Genoa and the proclamation of Napoleon as King of Italy on 17 March 1805. Sweden, which had already agreed to lease Swedish Pomerania as a military base for British troops against France, entered the coalition on 9 August. The Austrians began the war by invading Bavaria on 8 September 1805 with an army of about 70,000 under Karl Mack von Leiberich, and the French army marched out from Boulogne in late July 1805 to confront them. At Ulm (25 September – 20 October) Napoleon surrounded Mack's army, forcing its surrender without significant losses. With the main Austrian army north of the Alps defeated (another army under Archduke Charles fought against André Masséna's French army in Italy), Napoleon occupied Vienna on 13 November. Far from his supply lines, he faced a larger Austro–Russian army under the command of Mikhail Kutuzov, with the Emperor Alexander I of Russia personally present. On 2 December, Napoleon crushed the Austro–Russian force in Moravia at Austerlitz (usually considered his greatest victory). He inflicted 25,000 casualties on a numerically superior enemy army while sustaining fewer than 7,000 in his own force. Austria signed the Treaty of Pressburg (26 December 1805) and left the coalition. The treaty required the Austrians to give up Venetia to the French-dominated Kingdom of Italy and the Tyrol to Bavaria. With the withdrawal of Austria from the war, stalemate ensued. Napoleon's army had a record of continuous unbroken victories on land, but the full force of the Russian army had not yet come into play. Napoleon had now consolidated his hold on France, had taken control of Belgium, the Netherlands, Switzerland, and most of Western Germany and northern Italy. His admirers say that Napoleon wanted to stop now, but was forced to continue in order to gain greater security from the countries that refused to accept his conquests. Esdaile rejects that explanation and instead says that it was a good time to stop expansion, for the major