The Battle of Marengo was fought on 14 June 1800 between French forces under the First Consul Napoleon Bonaparte and Austrian forces near the city of Alessandria, in Piedmont, Italy. Near the end of the day, the French overcame Gen. Michael von Melas's surprise attack, driving the Austrians out of Italy and consolidating Napoleon's political position in Paris as First Consul of France in the wake of his coup dtat the previous November.Surprised by the Austrian advance toward Genoa in mid-April 1800, Bonaparte hastily led his army over the Alps in mid-May and reached Milan on 2 June. After cutting Melas line of communications by crossing the River Po and defeating Feldmarschallleutnant (FML) Peter Karl Ott von Btorkz at Montebello on 9 June, the French closed in on the Austrian army, which had massed in Alessandria. Deceived by a local double agent, Bonaparte dispatched large forces to the north and south, but the Austrians launched a surprise attack on 14 June against the main French army under Gen. Louis Alexandre Berthier.Initially their two assaults across the Fontanone stream near Marengo village were repelled, and Gen. Jean Lannes reinforced the French right. Bonaparte realized the true position and issued orders at 11:00 am to recall the detachment under Gnral de Division (GdD) Louis Desaix, while moving his reserve forward. On the Austrian left Ott's column had taken Castel Ceriolo, and its advance guard moved south to attack Lannes flank. Melas renewed the main assault and the Austrians broke the central French position. By 2:30 pm the French were withdrawing and Austrian dragoons seized the Marengo farm. Bonaparte had by then arrived with the reserve, but Berthier's troops began to fall back on the main vine belts. Knowing Desaix was approaching, Bonaparte was anxious about a column of Ott's soldiers marching from the north, so he deployed his Consular Guard infantry to delay it. The French then withdrew steadily eastward toward San Giuliano Vecchio as the Austrians formed a column to follow them, as Ott also advanced in the northern sector.Desaix's arrival around 5:30 pm stabilized the French position, as the 9th Light Infantry Regiment delayed the Austrian advance down the main road and the rest of the army reformed north of Cascina Grossa. As the pursuing Austrian troops arrived, a mix of musketry and artillery fire concealed the surprise attack of Gnral de Brigade (GdB) Franois tienne de Kellermanns cavalry, which threw the Austrian pursuit into disordered flight back into Alessandria, with about 14,000 killed, wounded or captured. The French casualties were considerably fewer, but included Desaix. The whole French line chased after the Austrians to seal une victoire politique (a political victory) that secured Bonaparte's grip on power after the coup. It would be followed by a propaganda campaign that sought to rewrite the story of the battle three times during Napoleon's rule.

Napoleon Bonaparte (born Napoleone di Buonaparte; 15 August 1769 – 5 May 1821) was a French military and political leader who rose to prominence during the French Revolution and led several successful campaigns during the Revolutionary Wars. He was the de facto leader of the French Republic as First Consul from 1799 to 1804. As Napoleon I, he was Emperor of the French from 1804 until 1814 and again in 1815. Napoleon dominated European and global affairs for a decade while leading France against a series of coalitions in the Napoleonic Wars. He won most of these wars and battles, building a large empire that ruled over continental Europe before its collapse in 1815. He was one of the greatest military commanders in history, and his wars and campaigns are studied in military schools worldwide. Napoleon's political and cultural legacy has endured, and he has been one of the most celebrated and controversial leaders in world history.Napoleon was born on the island of Corsica not long after its annexation by the Kingdom of France. He supported the French Revolution in 1789 while serving in the French army, and tried to spread its ideals to his native Corsica. He rose rapidly in the Army after he saved the governing French Directory by firing on royalist insurgents. In 1796, he began a military campaign against the Austrians and their Italian allies, scoring decisive victories and becoming a national hero. Two years later, he led a military expedition to Egypt that served as a springboard to political power. He engineered a coup in November 1799 and became First Consul of the Republic. Differences with the British meant that the French faced the War of the Third Coalition by 1805. Napoleon shattered this coalition with victories in the Ulm Campaign, and at the Battle of Austerlitz, which led to the dissolving of the Holy Roman Empire. In 1806, the Fourth Coalition took up arms against him because Prussia became worried about growing French influence on the continent. Napoleon knocked out Prussia at the battles of Jena and Auerstedt, marched the Grande Armée into Eastern Europe, annihilating the Russians in June 1807 at Friedland, and forcing the defeated nations of the Fourth Coalition to accept the Treaties of Tilsit. Two years later, the Austrians challenged the French again during the War of the Fifth Coalition, but Napoleon solidified his grip over Europe after triumphing at the Battle of Wagram.

Hoping to extend the Continental System, his embargo against Britain, Napoleon invaded the Iberian Peninsula and declared his brother Joseph King of Spain in 1808. The Spanish and the Portuguese revolted in the Peninsular War, culminating in defeat for Napoleon's marshals. Napoleon launched an invasion of Russia in the summer of 1812. The resulting campaign witnessed the catastrophic retreat of Napoleon's Grande Armée. In 1813, Prussia and Austria joined Russian forces in a Sixth Coalition against France. A chaotic military campaign resulted in a large coalition army defeating Napoleon at the Battle of Leipzig in October 1813. The coalition invaded France and captured Paris, forcing Napoleon to abdicate in April 1814. He was exiled to the island of Elba, between Corsica and Italy. In France, the Bourbons were restored to power. However, Napoleon escaped Elba in February 1815 and took control of France. The Allies responded by forming a Seventh Coalition, which defeated Napoleon at the Battle of Waterloo in June 1815. The British exiled him to the remote island of Saint Helena in the Atlantic, where he died in 1821 at the age of 51. Napoleon had an extensive impact on the modern world, bringing liberal reforms to the many countries he conquered, especially the Low Countries, Switzerland, and parts of modern Italy and Germany. He implemented liberal policies in France and Western Europe.