France, increasingly divided along religious lines, erupted into a succession of eight "Wars of Religion." In 1562, the Duke of Guise ordered the massacre of Huguenots worshiping in the Norman town of Vassy. More people were brutalized in Sens the same year.
It wasn’t a one-sided fight, however. Huguenots equally committed "frightful outrages" against Catholics.
Catherine de Medici, as Regent for her young son Charles IX, tried with some
success to make peace between Catholics and Protestants. Some accounts, however, put Catherine in the middle of the most significant event of France’s religious wars: The St. Bartholomew’s Day Massacre of 1572.
Although historians have debated the actual cause ever since, some of the facts are clear. Nineteen-year-old Henri of Navarre, the highest-ranking "prince of the blood" outside the immediate royal family, married Catherine de Medici’s daughter,
Marguerite de Valois, in Paris on August 17, 1572. Navarre (the future Henri IV) was a Huguenot. The royal family was Catholic.
Most high-ranking Huguenot nobles were in Paris to attend the wedding and its festivities. On the night of August 22, Admiral Gaspard de
Coligny (the Huguenot leader), met with the King. As the Admiral returned to his Paris lodgings, an assassin fired at him. Wounded - but not mortally - Coligny refused to leave Paris. He thought such actions would signal distrust of the King.
August 23rd was the Feast of St. Bartholomew. Henri of Navarre, his bride (whose account of the event survives - scroll down half-way to Letter V), and many Huguenot nobles were staying at the
Louvre. So, of course, were the King (Charles IX) and his mother (Catherine de Medici). Sometime during the night, it was decided to finish the action of Coligny’s would-be assassin.