Napoleon I (born Napoleone di Buonaparte, later Napoléon Bonaparte) was a general during the French Revolution, the ruler of France as First Consul (Premier Consul) of the French Republic, and Emperor of the French (Empereur des Français). He was also King of Italy, Mediator of the Swiss Confederation and Protector of the Confederation of the Rhine.

Born in Corsica and trained in mainland France as an artillery officer, he first rose to prominence as a general of the French Revolution, leading several successful campaigns against the First Coalition and the Second Coalition of neighboring powers opposed to the Revolution. In late 1799, Napoleon staged a coup d'ACtat to install himself as First Consul of France; five years later he crowned himself Emperor. Meanwhile, during the first decade of the nineteenth century the armies of France under his command fought almost every major European power, and gained control of most of continental Europe either by force of arms - through battlefield victories such as Austerlitz and Friedland - or by alliance systems. He went on to appoint several members of his family and close friends as monarchs and important government figures of French-dominated states.

A disastrous invasion of Russia in 1812 marked a turning point in Napoleon's fortunes. The campaign left his Grande Armée severely depleted in number and it never regained its previous strength. In October 1813, the Sixth Coalition defeated his forces at Leipzig and then invaded France. Napoleon was forced to abdicate in April of the following year and was exiled to the island of Elba. Less than a year later, he escaped to France and regained control of the government. This second period of Napoleonic rule, now known as the Hundred Days (les Cent Jours), ended quickly with his defeat at Waterloo on 18 June 1815. Napoleon spent the remaining six years of his life under British supervision on the island of St. Helena in the Atlantic Ocean.

Napoleon developed relatively few military innovations (though his placement of artillery into batteries and replacing the division with the army corps as the standard all-arms unit have become standard doctrine in virtually all large modern armies). Rather, he drew his best tactics from a variety of sources. He led the French army, modernized and reformed, to score several major victories. His campaigns are studied at military academies all over the world and he is widely regarded as one of history's greatest commanders. Aside from his military achievements, Napoleon is also remembered for the establishment of the Napoleonic Code (Code Napoléon), which laid the bureaucratic foundations for the modern French state.