War of the Third Coalition in the context of "French Revolutionary and Napoleonic Wars"

The Napoleonic Wars (1803–1815) were a global series of conflicts fought by a fluctuating array of European coalitions against the French First Republic (1803–1804) under the First Consul followed by the First French Empire (1804–1815) under the Emperor of the French, Napoleon Bonaparte. The wars originated in political forces arising from the French Revolution (1789–1799) and from the French Revolutionary Wars (1792–1802) and produced a period of French domination over Continental Europe. The wars are categorised as seven conflicts, five named after the coalitions that fought Napoleon, plus two named for their respective theatres: the War of the Third Coalition, War of the Fourth Coalition, War of the Fifth Coalition, War of the Sixth Coalition, War of the Seventh Coalition, the Peninsular War, and the French invasion of Russia.

The first stage of the war broke out when Britain declared war on France on 18 May 1803. After some minor campaigns, Britain allied with Austria, Russia, and several minor powers to form the Third Coalition in April 1805. Napoleon defeated the allied Russo-Austrian armies in the subsequent war which climaxed in French victories at Ulm and at Austerlitz, leading to the dissolution of the Holy Roman Empire and Austria being forced to make peace by the end of the year. Britain and Russia remained at war with France. Concerned about increasing French power, Prussia joined Britain and Russia in the Fourth Coalition, which resumed war in October 1806. Napoleon defeated the Prussians at Jena-Auerstedt and the Russians at Friedland, bringing an uneasy peace to the continent by July 1807, and again leaving Britain as France's sole major enemy. Britain was unable to dispute French dominance on the continent but obtained hegemony over the seas after a string of victories including Trafalgar. Russia used the interim peace to resolve wars with the Ottomans, Swedes, and Iranians.

The War of the Fifth Coalition was a European conflict in 1809 that was part of the Napoleonic Wars and the Coalition Wars. The main conflict took place in Central Europe between the Austrian Empire of Francis I and Napoleon's French Empire. The French were supported by their client states—the Kingdom of Italy, the Confederation of the Rhine and the Duchy of Warsaw. Austria was supported by the Fifth Coalition which included the United Kingdom, Portugal, Spain, and the Kingdoms of Sardinia and Sicily, although the latter two took no part in the fighting. By the start of 1809 much of the French army was committed to the Peninsular War against Britain, Spain and Portugal. After France withdrew 108,000 soldiers from Germany, Austria attacked France to seek the recovery of territories lost in the 1803–1806 War of the Third Coalition. The Austrians hoped Prussia would support them, having recently been defeated by France, but Prussia chose to remain neutral.

On 10 April 1809, Austrian forces under Archduke Charles crossed the border of Bavaria, a French client state. The French response, under Louis-Alexandre Berthier, was disorganised but order was imposed with the arrival of Napoleon on 17 April. Napoleon led an advance to Landshut, hoping to cut off the Austrian line of retreat and sweep into their rear. Charles crossed the Danube at Regensburg, which allowed him to retreat eastwards, although he failed to reach the Austrian capital, Vienna, before the French. A French assault across the Danube was repulsed on 21–22 May at the Battle of Aspern-Essling but a repeat attack was successful in July. Napoleon won a major victory at the 5–6 July Battle of Wagram, which forced the Austrians to sign the Armistice of Znaim on 12 July. Austrian invasions of the Duchy of Warsaw and Saxony (where they fought alongside the Black Brunswickers) were repulsed and they were driven out of their territories in Italy. British forces landed in Walcheren, in the French client state of Holland, but were unable to seize their objective of capturing Antwerp and later withdrew.

The War of the Fourth Coalition (French: Guerre de la Quatrième Coalition) was a war spanning 1806–1807 that saw a multinational coalition fight against Napoleon's French Empire, subsequently being defeated. The main coalition partners were Prussia and Russia with Saxony, Sweden, and Great Britain also contributing. Excluding Prussia, some members of the coalition had previously been fighting France as part of the Third Coalition, and there was no intervening period of general peace. On 9 October 1806, Prussia declared war on France and joined a renewed coalition, fearing the rise in French power after the defeat of Austria and establishment of the French-sponsored Confederation of the Rhine in addition to having learned of French plans to cede Prussian-desired Hanover to Britain in exchange for peace. Prussia and Russia mobilized for a fresh campaign with France, massing troops in Saxony.

Napoleon decisively defeated the Prussians in an expeditious campaign that culminated at the Battle of Jena–Auerstedt on 14 October 1806. French forces under Napoleon occupied Prussia, pursued the remnants of the shattered Prussian Army, and captured Berlin. They then advanced all the way to East Prussia, Poland and the Russian frontier, where they fought an inconclusive battle against the Russians at the Battle of Eylau on 7–8 February 1807. Napoleon's advance on the Russian frontier was briefly checked during the spring as he revitalized his army with fresh supplies. Russian forces were finally crushed by the French at the Battle of Friedland on 14 June 1807, and three days later Russia asked for a truce.

The Ulm campaign was a series of French and Bavarian military maneuvers and battles to outflank and capture an Austrian army in 1805 during the War of the Third Coalition. It took place in the vicinity of and inside the Swabian city of Ulm. The French Grande Armée, led by Emperor Napoleon, had 210,000 troops organized into seven corps and hoped to knock out the Austrian army in the Danube before Russian reinforcements could arrive. Rapid marching let Napoleon conduct a large wheeling maneuver, which captured an Austrian army of 60,000 under Feldmarschall-Leutnant (FML) Karl Freiherr Mack von Leiberich on 20 October at Ulm. The campaign is by some military historians regarded as a strategic masterpiece and was influential in the development of the Schlieffen Plan in the late 19th century. Napoleon himself wrote:

The victory at Ulm did not end the war since a large Russian army under Mikhail Kutuzov was near Vienna to defend the city against the French. The Russians withdrew to the northeast to await reinforcements and to link up with Austrian army units. The French moved aggressively forward and captured Vienna on 12 November. On 2 December, the massive Battle of Austerlitz, causing 24,000 to 36,000 casualties, removed Austria from the war. The resulting Treaty of Pressburg in late December brought the Third Coalition to an end and established Napoleonic France as the major power in Central Europe, which led to the War of the Fourth Coalition against the Kingdom of Prussia and Russia the following year.

The Battle of Austerlitz (2 December 1805/11 Frimaire An XIV FRC), also known as the Battle of the Three Emperors, was one of the most important military engagements of the Napoleonic Wars. The battle occurred near the town of Austerlitz in the Austrian Empire (now Slavkov u Brna in the Czech Republic). Around 158,000 troops were involved, of which around 24,000 were killed or wounded.

The battle is often cited by military historians as one of Napoleon's tactical masterpieces, in the same league as other historic engagements like Hannibal's Cannae (216 BC) or Alexander the Great's Gaugamela (331 BC). The military victory of Napoleon's Grande Armée at Austerlitz brought the War of the Third Coalition to an end, with the Peace of Pressburg signed by the French and Austrians later in the month. These achievements did not establish a lasting peace on the continent. Austerlitz had driven neither Russia nor Britain, whose armies protected Sicily from a French invasion, to settle. Prussian resistance to France's growing military power in Central Europe led to the War of the Fourth Coalition in 1806.

The Battle of Trafalgar was a naval engagement that took place on 21 October 1805 between the Royal Navy and a combined fleet of the French and Spanish navies during the War of the Third Coalition. As part of Napoleon's planned invasion of the United Kingdom, the French and Spanish fleets combined to take control of the English Channel and provide the Grande Armée safe passage. The allied fleet, under the command of French admiral Pierre-Charles Villeneuve, sailed from the port of Cádiz in the south of Spain on 18 October 1805. They encountered a British fleet under Lord Nelson, recently assembled to meet this threat, in the Atlantic Ocean along the southwest coast of Spain, off Cape Trafalgar.

Nelson was outnumbered, with 27 British ships of the line to 33 French and Spanish, including the largest warship in either fleet, the Spanish Santísima Trinidad. To address this imbalance, Nelson sailed his fleet directly at the allied battle line's flank in two columns, hoping to break the line into pieces. Villeneuve had worried that Nelson might attempt this tactic, but for various reasons, failed to prepare for it. To add to the French crisis, their crews were inexperienced and poorly trained. The British plan worked almost perfectly; Nelson's columns split the Franco-Spanish fleet in three, isolating the rear half from Villeneuve's flag aboard Bucentaure. The allied vanguard sailed off while it attempted to turn around, giving the British temporary superiority over the remainder of their fleet. In the ensuing fierce battle 18 allied ships were captured or destroyed, while the British lost none.

The Grande Armée (pronounced [ɡʁɑ̃d aʁme]; French for 'Grand Army') was the primary field army of the French Imperial Army during the Napoleonic Wars. Commanded by Napoleon, from 1804 to 1808 it won a series of military victories that allowed the First French Empire to exercise unprecedented control over most of Europe. Widely acknowledged to be one of the greatest fighting forces ever assembled, it suffered catastrophic losses during the disastrous French invasion of Russia, after which it never recovered its strategic superiority and ended its military career with a total defeat during the Hundred Days in 1815.

The Grande Armée was formed in 1804 from the Armée des côtes de l'Océan (Army of the Ocean Coasts) more commonly referred to as the Armée d'Angleterre (Army of England), a field army of over 100,000 men assembled for Napoleon's planned invasion of the United Kingdom. He subsequently led the field army to Central Europe and defeated Austrian and Russian forces as part of the War of the Third Coalition. Thereafter, the Grande Armée was the principal field army deployed in the War of the Fourth Coalition, Peninsular War and War of the Fifth Coalition, where the French army slowly lost a large portion of its veteran soldiers, strength and prestige, and in the invasion of Russia, War of the Sixth Coalition and Hundred Days. The term Grande Armée is often used to refer to multinational armies led by Napoleon in his campaigns; however, during the War of the Fifth Coalition and the Waterloo campaign (part of the Hundred Days), other formations were led by him de facto, namely the Army of Germany and the Army of the North, respectively.