The violence happened more and more often in June and July of 1794 , a period called la Grande Terreur ( The Great Terror ) , which ended 27 July 1794 , when several important leaders of the Reign of Terror were executed , including Saint-Just and Robespierre . The repression accelerated in June and July 1794 , a period called `` la Grande Terreur '' ( the Great Terror ) , and ended in the coup of 9 Thermidor Year II ( 27 July 1794 ) , the so-called `` Thermidorian Reaction '' , in which several leaders of the Reign of Terror were executed , including Saint-Just and Robespierre .