Revolutionary crowds massacred 1200 royalist prisoners blamed for military defeats

Evidence

Between 2 and 5 September 1792, at the insistence notably of Marat, some 1200 royalist prisoners were massacred. They were accused of having by their treachery brought about the defeats suffered by the revolutionary annies prior to the battle of Valmy. — Antonio Gramsci, Selections from the Prison Notebooks, 1954