In the Napoleonic Wars, the Fourth Coalition was an alliance organized against Napoleon's Empire of France in 1806–1807. Coalition partners included Britain, Prussia, Russia, Saxony, and Sweden.

Many members of the coalition had previously been fighting France as part of the Third Coalition, and there was no intervening period of peace. In 1806, Prussia joined the coalition fearing the rise in French power after the defeat of Austria. Prussia and Russia mobilized for a fresh campaign, and Prussian troops massed in Saxony.

Napoleon counterattacked, and defeated the Prussians decisively at Jena-Auerstedt in October 1806. French forces under Napoleon occupied Prussia, capturing Berlin on October 25 1806 and moving all the way to East Prussia and the Russian frontier, where they fought an inconclusive battle against the Russians at Eylau in February 1807; Napoleon's advance on the Russian frontier was briefly checked. Russian forces were crushed by Napoleon's army at Friedland on June 14, 1807, and three days later Russia asked for a truce. By the Treaties of Tilsit in July 1807, France made peace with Russia and forced Prussia to give up half of its territory to France, Jerome Bonaparte's Kingdom of Westphalia, and the new Grand Duchy of Warsaw. Napoleon was virtually in control of western and central Europe.

See also

• Napoleonic Wars
• First Coalition
• Second Coalition
• Third Coalition
• Fifth Coalition
• Sixth Coalition
• Seventh Coalition