The Reign of Terror ended with the arrest and execution of its leading architect, Maximilien Robespierre, and several of his allies in July 1794, triggering the Thermidorian Reaction that rolled back the most radical phase of the revolution. The collapse came after growing opposition within the National Convention and among other political factions as the revolutionary government faced military threats, internal dissent, and the perception that the Terror was spiraling out of control. Robespierre was arrested on 9 Thermidor (July 27, 1794) and executed the following day, effectively ending the Terror and giving way to a more conservative, less centralized phase of the Revolution.