In the history of France, the First Republic, officially the French Republic (French: République française), was founded on 21 September 1792 during the French Revolution. The First Republic lasted until the declaration of the First Empire in 1804 under Napoleon, although the form of the government changed several times. This period was characterized by the fall of the monarchy, the establishment of the National Convention and the Reign of Terror, the Thermidorian Reaction and the founding of the Directory, and, finally, the creation of the Consulate and Napoleon's rise to power.
Under the Legislative Assembly, which was in power before the proclamation of the First Republic, France was engaged in war with Prussia and Austria. In July 1792, the Duke of Brunswick, commanding general of the Austro–Prussian Army, issued his Brunswick Manifesto, in which he threatened the destruction of Paris should any harm come to King Louis XVI. The foreign threat exacerbated France's political turmoil amid the French Revolution and deepened the passion and sense of urgency among the various factions. In the violence of 10 August 1792, citizens stormed the Tuileries Palace, killing six hundred of the King's Swiss guards and insisting on the removal of the king. A renewed fear of anti-revolutionary action prompted further violence, and in the first week of September 1792, mobs of Parisians broke into the city's prisons, killing over half of the prisoners. This included nobles, clergymen, and political prisoners, but also numerous common criminals, such as prostitutes and petty thieves, many murdered in their cells—raped, stabbed, and slashed to death. This became known as the September Massacres.