1806-1807 - (Fourth) War with Prussia and Russia

The death of Pitt (Jan. 23, 1806) led to negotiations between Napoleon and Fox, the new Foreign Secretary: These negotiations, as well as those with Russia, came to naught, and to Napoleon's surprise this failure was coupled with the decision on the part of Frederick William III of Prussia to make war upon him. Single-handed Prussia undertook to meet Napoleon, who, as soon as he foresaw that war was inevitable, acted with the same vigor as in the previous year. The Prussian army under Prince Hohenlohe-Ingelfingen and Charles William Ferdinand, Duke of Brunswick, was drawn out in a line 85 miles in length, extending from Gera westward to the borders of Hesse-Cassel, with the bulk at Erfurt.

Napoleon left Paris on September 25 and assumed charge of the campaign at WUrzburg on October 2. On the 10th Prince Louis Ferdinand was defeated and slain in a skirmish at Saalfeld; on the 14th Napoleon surprised the Prussian army in its attempt to concentrate, and in person defeated Hohenlohe at Jena, while Davout defeated Brunswick at Auerstadt. Murat and Lannes pursued Hohenlohe and forced him to surrender at Prenzlau (October 28), while the other remnants of the Prussian army and the fortresses surrendered without a blow. Saxony, which had acted as the ally of Prussia, went over to Napoleon, and later received as reward the Duchy of Warsaw. From the Prussian capital Napoleon issued the Berlin Decree, which, with the Milan Decree of 1807 and other decrees, establishing the Continental System directed against English commerce.

Prussia, though vanquished, continued weakly the struggle in her eastern provinces, where Bennigsen and the Russians were ready to join in the contest. Murat occupied Warsaw, then Prussian territory, in November, 1806. In December Napoleon entered the ancient Polish capital and was greeted as the restorer of Polish liberties. The French having gone into winter quarters, Bennigsen hoped to surprise them and destroy them before they could again take the field, and accordingly attacked Ney and Bernadotte, but their successful resistance defeated the plan and Napoleon in person pursued Bennigsen, who retreated toward Konigsberg, and overtook him at Eylau. The ensuing battle (Feb. 7-8, 1807) was a butchery, not a victory.

Napoleon hurried up reinforcements to renew the struggle in the spring. Sebastiani, the French Ambassador at Constantinople, persuaded the Sultan to declare war against Russia. Gardane was sent to stir up Persia to like action. Mortier induced the Swedes to treat with France. The campaign for Konigsberg began early in June and was marked by the indecisive action of Heilsberg (June 10) and the defeat, four days later, of the Russians under Bennigsen at Friedland. On June 25 the Czar and Napoleon held their famous conference of Tilsit on a raft moored in the Niemen. By the Treaty of Tilsit Prussia was humbled even more than Austria had been at Pressburg, while the Czar became the ally of Napoleon and began to plan with him the division of the world between them.