French) in 1572 was a targeted group of assassinations, followed by a wave of Roman Catholic mob violence, both directed against the Huguenots (French Calvinist Protestants), during the French Wars of Religion. Traditionally believed to have been instigated by Catherine de' Medici, the mother of King Charles IX, the massacre took place six days after the wedding of the king's sister Margaret to the Protestant Henry III of Navarre (the future Henry IV of France). This marriage was an occasion for which many of the most wealthy and prominent Huguenots had gathered in largely Catholic Paris.
The massacre began two days after the attempted assassination of Admiral Gaspard de Coligny, the military and political leader of the Huguenots. Starting on 23 August 1572 (the eve of the feast of Bartholomew the Apostle) with murders on orders of the king of a group of Huguenot leaders including Coligny, the massacres spread throughout Paris. Lasting several weeks, the massacre extended to other urban centres and the countryside. Modern estimates for the number of dead vary widely between 5,000 and 30,000 in total.
The massacre also marked a turning point in the French Wars of Religion. The Huguenot political movement was crippled by the loss of many of its prominent aristocratic leaders, as well as many re-conversions by the rank and file, and those who remained were increasingly radicalized. Though by no means unique, it "was the worst of the century's religious massacres."  Throughout Europe, it "printed on Protestant minds the indelible conviction that Catholicism was a bloody and treacherous religion".