The War of the Fourth Coalition was fought between France and an alliance of Prussia, Russia, Saxony, Sweden, and Britain from 1806 to 1807. It was notable above all for the extraordinary speed with which Napoleon destroyed Prussia as a military power, routing two Prussian armies simultaneously at the twin battles of Jena and Auerstedt in October 1806 and occupying Berlin within days. He then fought a longer and harder campaign against Russia, eventually winning a decisive victory at the Battle of Friedland in June 1807. The war ended with the Treaties of Tilsit in July 1807, one of the most dramatic diplomatic settlements of the entire Napoleonic period, in which Napoleon and Tsar Alexander I met on a raft in the middle of the Niemen River and effectively divided Europe between their two empires. The Treaties of Tilsit represented the high point of Napoleon’s power, leaving France dominant over virtually the entire European continent.
What Was the Napoleonic Era?
The Napoleonic Era refers to the period of French and European history dominated by Napoleon Bonaparte, lasting from his seizure of power in France in 1799 to his final defeat and exile in 1815. The Fourth Coalition was one of a series of alliances formed by the major European powers to challenge French dominance, each of which was defeated in turn by Napoleon’s military genius. The Fourth Coalition formed in the immediate aftermath of Napoleon’s crushing victory over Austria and Russia at Austerlitz in December 1805, as Prussia, alarmed by the dramatic shift in European power that the war had produced, finally decided to challenge France directly.
War of the Fourth Coalition – Background and Causes
Prussia had remained neutral during the War of the Third Coalition in 1805, despite being approached by both sides. Its neutrality had been a serious miscalculation. The French victory at Austerlitz and the subsequent Treaty of Pressburg dramatically extended French power across Central Europe, bringing the Confederation of the Rhine under French protection and dissolving the Holy Roman Empire. Prussia found itself increasingly surrounded by French client states and facing a France more powerful than ever.
Several specific grievances pushed Prussia toward war in 1806. Napoleon’s high-handed treatment of German affairs, including his reorganization of territories without consulting Prussia, caused deep resentment. More specifically, Napoleon had offered to return Hanover to Britain as part of peace negotiations without consulting Prussia, which had itself been offered Hanover by France only months earlier. This diplomatic double-dealing was a direct insult to Prussian dignity that the Prussian court could not ignore.
Prussia was also encouraged by the belief, misguided as it would prove, that its army was still the formidable force it had been under Frederick the Great. The Prussian military had not been fundamentally reformed since Frederick’s death in 1786, and many of its senior commanders were elderly men who had fought under the great king himself and who believed his methods remained adequate for modern warfare. This confidence was deeply misplaced. In September 1806 Prussia issued an ultimatum to France demanding the withdrawal of French forces from German territory, and when Napoleon ignored it, Prussia declared war.
War of the Fourth Coalition – The Destruction of Prussia
Napoleon moved with his characteristic speed against Prussia. The French campaign opened on October 8th, 1806, and within six days it had effectively destroyed the Prussian army. On October 14th, 1806, two major battles were fought simultaneously at Jena and Auerstedt, two towns roughly fifteen miles apart in what is now the German state of Thuringia.
At Jena, Napoleon himself commanded the main French force against a Prussian army under Prince Friedrich of Hohenlohe. The battle was a comprehensive French victory that shattered the Prussian forces engaged there. At the same moment, at Auerstedt, Marshal Davout’s corps of around 26,000 men faced the main Prussian army of approximately 60,000 under the Duke of Brunswick. Despite being outnumbered more than two to one, Davout won a remarkable victory, killing the Duke of Brunswick and routing the Prussian force through superior tactical skill and the fighting quality of his troops. The twin victories at Jena and Auerstedt on a single day effectively destroyed Prussia’s capacity to resist.
The collapse of the Prussian army was total and rapid. Napoleon pursued the broken Prussian forces aggressively, capturing fortresses and towns that surrendered almost without resistance as the Prussian military system disintegrated. French forces captured Berlin on October 25th, 1806, less than two weeks after the battles. The Prussian royal family, King Frederick William III and his famous and admired Queen Louise, fled eastward to the far corner of their kingdom near Königsberg, where they sought refuge close to the approaching Russian forces.
From Berlin, Napoleon issued the Berlin Decree on November 21st, 1806, formally establishing the Continental System, his attempt to defeat Britain through economic warfare by blockading British trade from the European continent.
War of the Fourth Coalition – The Campaign Against Russia
With Prussia effectively knocked out of the war, Napoleon turned east to deal with the Russian army under General Bennigsen, which was advancing to link up with the remnants of Prussian resistance. The French army crossed the Vistula River in December 1806 and advanced into Poland. Napoleon established a provisional Polish administration and raised Polish troops who fought alongside the French, raising hopes among Polish patriots that Napoleon would restore Polish independence.
The campaign against Russia proved far harder than the destruction of Prussia had been. The first major engagement, the Battle of Eylau on February 7th and 8th, 1807, fought in bitterly cold conditions with heavy snow in East Prussia, was a bloody and inconclusive drawn battle that left both sides battered. The French suffered significant casualties without achieving a decisive result, and Napoleon was forced to acknowledge that the Russian army was a far more resilient opponent than the Prussians had been. Both sides withdrew into winter quarters to rest and refit.
When campaigning resumed in the spring of 1807, Napoleon maneuvered to bring Bennigsen to a decisive engagement. The opportunity came at the Battle of Friedland on June 14th, 1807, near the town of Friedland in East Prussia, now part of modern Russia. Bennigsen had placed his army in a poor tactical position with a river at its back, and Napoleon recognized the opportunity immediately. The French launched a powerful attack that drove the Russian forces into the town and against the river, inflicting approximately 20,000 casualties and routing the Russian army. Three days later Russia asked for a truce.
War of the Fourth Coalition – The Treaties of Tilsit
The peace negotiations that followed the Battle of Friedland produced one of the most celebrated diplomatic encounters of the Napoleonic era. Napoleon and Tsar Alexander I met for the first time on June 25th, 1807, on a specially constructed raft moored in the middle of the Niemen River, the border between French-controlled territory and Russian-held ground. King Frederick William III of Prussia waited on the riverbank, pointedly excluded from the initial meeting. The two emperors met privately for several hours and reportedly got on well personally, with Alexander reportedly opening the conversation by declaring his hatred of England, to which Napoleon replied that in that case peace was already made.
The negotiations produced two separate treaties, both signed in the nearby town of Tilsit. The first, signed on July 7th, 1807 between Napoleon and Alexander, was relatively favorable to Russia. Alexander recognized the Confederation of the Rhine, acknowledged the new French client states Napoleon had created in Europe, and agreed to join the Continental System, ending Russian trade with Britain. Russia lost minimal territory of its own, receiving only the small district of Bialystok from Prussia as compensation.
The second treaty, signed on July 9th, 1807 with Prussia, was far harsher. Prussia was stripped of approximately half its pre-war territory. The Polish lands Prussia had acquired through the partitions of Poland were used to create the new Grand Duchy of Warsaw, placed under the rule of Napoleon’s ally the King of Saxony and serving as a French client state on Russia’s western border. Prussia’s territories west of the Elbe River were reorganized into the new Kingdom of Westphalia, placed under the rule of Napoleon’s youngest brother Jerome Bonaparte. Prussia was required to reduce its army to a maximum of 42,000 men and to pay a massive war indemnity of 154 million francs. The Prussian royal family had pleaded for more lenient terms, with Queen Louise personally appealing to Napoleon in an emotional meeting that was widely reported across Europe, but Napoleon was largely unmoved and the harsh terms stood.
War of the Fourth Coalition – Significance
The significance of the War of the Fourth Coalition in the history of the Napoleonic Era is considerable. The war demonstrated the full extent of Napoleon’s military superiority over the continental European powers and established French dominance over the continent at its greatest extent. The destruction of Prussia as a first-rank military power in a matter of days was one of the most stunning demonstrations of rapid decisive warfare in the history of European conflict and sent a shock through European military thinking that drove subsequent efforts at reform, particularly in Prussia itself, where the experience of Jena and Auerstedt prompted a fundamental reorganization of the Prussian military system under reformers such as Scharnhorst and Gneisenau.
The Treaties of Tilsit represented the high-water mark of Napoleon’s power. For a brief period after July 1807, virtually the entire European continent was either under French control, allied with France, or neutralized. Only Britain remained at war, undefeated behind its naval shield. In reality, however, the settlement contained the seeds of its own undoing. Russia’s commitment to the Continental System proved damaging to its economy and deeply unpopular, and Alexander’s willingness to maintain the alliance with France steadily eroded over the following years. The harsh treatment of Prussia planted a deep resentment that eventually drove the Prussian military reforms and the nationalist awakening that would contribute to Napoleon’s defeat in 1813. As such, the War of the Fourth Coalition stands as both the greatest triumph and the beginning of the long decline of Napoleon’s European empire.
