St. Bartholomew's Day massacre St. Bartholomew's Day massacre The St. Bartholomew's Day massacre () in 1572 was a targeted group of assassinations and a wave of Catholic mob violence, directed against the Huguenots (French Calvinist Protestants) during the French Wars of Religion. Traditionally believed to have been instigated by Queen Catherine de' Medici, the mother of King Charles IX, the massacre took place a few days after the wedding day (18 August) of the king's sister Margaret to the Protestant Henry III of Navarre (the future Henry IV of France). Many of the most wealthy and prominent Huguenots had gathered in largely Catholic Paris
St. Bartholomew's Day massacre response to the threatening atmosphere for Huguenots in these cities. In Rouen, where some hundreds were killed, the Huguenot community shrank from 16,500 to fewer than 3,000 mainly as a result of conversions and emigration to safer cities or countries. Some cities unaffected by the violence nevertheless witnessed a sharp decline in their Huguenot population. It has been claimed that the Huguenot community represented as much as 10% of the French population on the eve of the St. Bartholomew's Day massacre, declining to 7-8% by the end of the 16th century, and further after heavy persecution began once again during