The “September Massacres” refers to the slaughter of political prisoners in France. These killings took place mainly in Paris from 2 to 6 September 1792, during the French Revolution, when fear of invasion and counterrevolution reached a fever pitch.
Parisian crowds, revolutionary volunteers, and guards attacked prisons including the Abbey, Carmes, La Force, and the Conciergerie. Many victims were non-juring Catholic priests and suspected royalists, but ordinary prisoners were also killed. The attackers often conducted improvised “trials” before carrying out summary executions.
The immediate background was the Brunswick Manifesto, which threatened Paris if the royal family were harmed, combined with news that Prussian forces were advancing. Revolutionaries feared that imprisoned enemies would break out and attack the city from within. Estimates vary, but roughly 1,100 to 1,600 people died in Paris, with additional violence elsewhere in France.
A common mix-up is treating the massacres as a single battle or as an event limited to political prisoners. They were a series of prison killings in revolutionary France, and their brutality later became a major symbol of the Revolution’s radicalization.