Why it happened
France in the late 1780s was simultaneously the most populous country in Europe and one of the most fiscally distressed. The combination of long-term military expenditure (including support for the American Revolution), an inefficient and inequitable tax system that exempted the nobility and the clergy from most direct taxes, several years of poor harvests (themselves possibly amplified by the 1783 Laki eruption in Iceland), and a politically isolated monarchy under Louis XVI produced a crisis the existing institutions could not manage.
In May 1789, faced with state bankruptcy, Louis XVI convened the Estates-General — the traditional French representative body, which had not met since 1614. The Third Estate (commoners), representing approximately 97% of the population, refused to be outvoted by the First Estate (clergy) and Second Estate (nobility) and on 17 June declared itself the National Assembly. On 14 July a Parisian crowd stormed the Bastille fortress in eastern Paris. The revolution had begun.
The phases
The Revolution moved through several distinct phases:
Constitutional Monarchy (1789–1792). The National Assembly abolished feudal privileges (4 August 1789), issued the Declaration of the Rights of Man and of the Citizen (26 August 1789), and confiscated Church lands. A constitutional monarchy was established in 1791. Louis XVI attempted to flee France in June 1791 and was captured at Varennes.
The First Republic and the Terror (1792–1794). The monarchy was abolished in September 1792 after the French armies’ early defeats in the Revolutionary Wars. Louis XVI was tried and executed on 21 January 1793. The radical Jacobin faction under Maximilien Robespierre directed the Reign of Terror from September 1793 to July 1794, in which approximately 17,000 people were formally executed (and roughly the same number again died in prison or in extrajudicial violence). The Terror ended with Robespierre’s own execution on 28 July 1794 (the 9 Thermidor in the revolutionary calendar).
The Directory (1795–1799). A more conservative republican government, the Directory, ruled France through five years of continuing war, economic crisis, and political instability. It was overthrown on 9 November 1799 in a coup led by the young general Napoleon Bonaparte (coup de 18 Brumaire).
The wars
The Revolutionary Wars (1792–1802) and the subsequent Napoleonic Wars (1803–1815) involved France against successive coalitions of European powers. The wars killed approximately 3.5 million soldiers and civilians across Europe and reshaped the continent’s political map.
Legacy
The French Revolution established several principles that became foundational to modern political thought: popular sovereignty, the equality of citizens before the law, the separation of church and state, codified rights, and the secular nation-state. The Declaration of the Rights of Man and of the Citizen is one of the source documents of modern human-rights law.
France itself spent the following century cycling through political systems — the First Republic, the First Empire under Napoleon, the Restored Bourbon Monarchy, the July Monarchy, the Second Republic, the Second Empire under Napoleon III — before finally settling into the Third Republic (1870–1940) under which figures like Félix Faure presided over the Belle Époque and the Dreyfus Affair.