Despite the efforts of numerous people to spread the reformation throughout France progress was slow. Frustrated by the glacial pace a handful of reformists decided the movement needed bold strokes. They wrote an article denouncing the mass in the strongest, most offensive words. The article was transcribed onto large placards or posters which were plastered on church doors. One brave soul went so far as to attach one to the door of the King’s bed chamber. France woke up to offensive, inflammatory posters tearing apart an institution they held as sacrosanct. The violation was too much to bear. The backlash was swift and immediate, beginning with arrests, and burnings. Thousands of French Protestants were forced to flee the country, including John Calvin, who escaped to Straousburg for refuge. As an act of penance, the king called for a day of national mourning and repentance. The Affair of the Placards was a turning point in the French Reformation. It polarised the nation, creating a clear demarcating line between Catholics and Protestants, fanning flames of open hostility and hatred. After the placards, France openly opposed the Reformation, and persecution against reformists known as Huguenots steadily increased. 

Many reformists who fled France during the Affair of the Placards found refuge in Geneva. Here, under the guidance of men like William Farel and John Calvin, hundreds of young Frenchmen were trained as pastors. They returned to France undercover, quietly evangelized the country, and set up a network of over a thousand underground Huguenot churches throughout the kingdom. This new movement soon became the target of intense persecution and the focal point of what became known as the French Wars of Religion.