On 9 Thermidor Year II (27 July 1794), the French politician Maximilien Robespierre was denounced by members of the National Convention as 'a tyrant', leading to Robespierre and twenty-one associates including Louis Antoine de Saint-Just to be arrested that night and to be beheaded on 28 July.

The name Thermidorian refers to 9 Thermidor Year II (27 July 1794), the date according to the French Republican Calendar when Robespierre and other radical revolutionaries came under concerted attack in the National Convention. Thermidorian Reaction also refers to the remaining period until the National Convention was superseded by the Directory; this is also sometimes called the era of the Thermidorian Convention. Prominent figures of Thermidor include Paul Barras, Jean-Lambert Tallien, and Joseph Fouché.

Thermidor represents the final throes of the Reign of Terror. With Robespierre the sole remaining strong-man of the Revolution following the assassination of Jean-Paul Marat (13 July 1793), and the executions of Jacques Hébert (24 March 1794), Georges Danton and Camille Desmoulins (5 April 1794), his apparently total grasp on power became in fact increasingly illusory, especially insofar as he seemed to have support from factions to his right. His only real political power at this time lay in the Jacobin Club, which had extended itself beyond the borders of Paris and into the country as a network of "Popular Societies". In addition to widespread reaction to the Reign of Terror, Robespierre's tight personal control of the military, his distrust of military might and of banks, and his opposition to supposedly corrupt individuals in government, made him the subject of a number of conspiracies.

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