Final answer:
The estimated 40,000 people executed by the guillotine during the French Revolution were victims of the Reign of Terror, a period of extreme violence and political repression from 1793 to 1794.
Step-by-step explanation:
The estimated 40,000 people who were executed by the guillotine in one year during the French Revolution were victims of the Reign of Terror. The Reign of Terror was a period characterized by extreme violence and the execution of numerous enemies of the revolutionary government from 1793 to 1794. It was a time of political instability and repression, where anyone perceived as a threat to the revolution or the state could be arrested and executed.