The phases
The Napoleonic Wars are conventionally treated as seven coalition wars between France and shifting alliances of European powers. The wars were continuous with the earlier French Revolutionary Wars (1792–1802) but conventionally dated from the resumption of war between France and Britain in May 1803.
Third Coalition (1803–1806): Britain, Austria, Russia, Sweden vs France. Decided by the Battle of Austerlitz (2 December 1805), which destroyed the combined Austrian-Russian army and produced the Treaty of Pressburg dissolving the Holy Roman Empire. British naval supremacy was confirmed at the Battle of Trafalgar (21 October 1805), at which Admiral Horatio Nelson’s fleet decisively defeated the combined Franco-Spanish fleet off the southwestern Spanish coast. Nelson was killed in the battle.
Fourth Coalition (1806–1807): Britain, Prussia, Russia, Sweden vs France. Decided by the Battle of Jena-Auerstedt (14 October 1806), which destroyed the Prussian army in a single day, and Friedland (June 1807), which forced Russia to terms at the Treaty of Tilsit (July 1807). The Tilsit settlement briefly brought Russia into alliance with France.
Peninsular War (1808–1814): French occupation of Spain and Portugal, opposed by Spanish, Portuguese, and British forces under Arthur Wellesley (the future Duke of Wellington). Six years of sustained guerrilla warfare and conventional campaigning. The Peninsular front consumed approximately 300,000 French troops over the war and is conventionally cited as one of the most consequential strategic drains on the Napoleonic system.
Fifth Coalition (1809): Britain, Austria vs France. Decided by the Battle of Wagram (5–6 July 1809) — the largest battle in European history to that date, with approximately 300,000 troops engaged.
Russian campaign (1812): The single most consequential military operation of the entire wars. Napoleon invaded Russia with approximately 685,000 troops in June 1812. The army reached Moscow on 14 September 1812; the Russians had abandoned and burned the city. With no opposing army to defeat, no political surrender forthcoming, and winter approaching, Napoleon began the retreat in late October. The army was destroyed by cold, starvation, partisan attack, and the Russian winter pursuit. Approximately 100,000 survivors recrossed the Niemen in December 1812.
Sixth Coalition (1813–1814): Britain, Austria, Prussia, Russia, Sweden, Spain, Portugal, smaller German states vs France. The depleted French armies were progressively pushed back. The decisive engagement was the Battle of Leipzig (16–19 October 1813), the largest land battle in European history before the First World War — approximately 600,000 troops engaged, approximately 100,000 casualties. The coalition entered Paris on 31 March 1814. Napoleon abdicated on 6 April and was exiled to Elba.
Seventh Coalition (1815): The Hundred Days, Napoleon’s return from Elba and final defeat. The decisive engagement was Waterloo (18 June 1815), where combined British-Dutch and Prussian forces under Wellington and Blücher destroyed Napoleon’s last army. Napoleon abdicated, surrendered to the British, and was exiled to Saint Helena.
The continental system and the British blockade
The wars produced one of the largest sustained economic-warfare campaigns of pre-modern history. Napoleon’s Continental System (formalized by the Berlin Decree of November 1806 and the Milan Decree of December 1807) attempted to exclude British trade from continental Europe — closing all continental ports to British shipping and embargoing British goods. The Royal Navy’s response was a counter-blockade that effectively closed the Atlantic and the Mediterranean to neutral shipping that traded with continental Europe.
The system was substantially unenforceable. Smuggling across the European coastal frontiers — particularly in the Baltic, the Iberian peninsula, and the Adriatic — undermined the embargo. Russia’s de facto withdrawal from the Continental System in late 1810 was a substantial trigger of the 1812 invasion. The system did, however, produce sustained economic disruption across continental Europe, accelerated the institutional consolidation of post-Napoleonic European states’ protectionist trade policies, and contributed to the political-economic conditions that produced the War of 1812 between Britain and the United States.
Casualties
The wars killed approximately 3.5 million soldiers and civilians, by mid-range modern estimates. Approximately 1 million French soldiers died (out of a French population of approximately 30 million — proportionally comparable to French losses in WWI). Russia, Prussia, Austria, Spain, and the United Kingdom each lost between 100,000 and 500,000 military dead. Civilian casualties from disease, famine, and direct violence were substantial across the war zones; the Spanish Peninsular War alone may have killed 500,000 Spanish civilians.
The Congress of Vienna
The post-war political settlement was negotiated at the Congress of Vienna (November 1814 – June 1815) under the leadership of the Austrian foreign minister Metternich. The Congress reorganized the territorial map of Europe to restore (where possible) pre-Napoleonic political legitimacy, established the Concert of Europe as an ongoing diplomatic framework for the maintenance of European political stability, and inaugurated approximately a century of relative European peace until the outbreak of the First World War.
The Vienna settlement explicitly rejected the revolutionary-Napoleonic political-territorial reorganization while preserving the institutional reforms (the Civil Code, the meritocratic civil service, the post-feudal property regime) that Napoleonic occupation had introduced into the conquered states. The 19th-century European political order — the Restoration monarchies, the Holy Alliance, the long peace, and the gradual emergence of nationalist movements — was the direct product of the 1814–1815 settlement.
Legacy
The Napoleonic Wars produced the modern European political-territorial map (substantially intact until 1914), the institutional reforms of the Napoleonic state across continental Europe, the British political-economic dominance of the 19th century, the long peace under the Concert of Europe, and the political-cultural inheritance of military glory and national-state identity that would shape European political imagination through the 19th century. They are also a foundational case study in the limits of military operations against opponents who can absorb operational defeats and continue to mobilize political-economic resources for sustained warfare.