The St. Bartholomew's Day Massacre, which occurred in August 1572, had a significant impact on France. The event, in which thousands of French Protestants, also known as Huguenots, were killed by Catholics, marked the beginning of the Wars of Religion in France. The massacre, which was instigated by Catherine de' Medici and her son King Charles IX, led to increased religious tension and violence in the country. It also resulted in a large number of Huguenots fleeing France, which had a negative impact on the country's economy. Additionally, the massacre damaged France's reputation in Europe and contributed to the country's political instability.