Excerpts from Books and Wikipedia
Henry IV issued the Edict of Nantes, introducing religious toleration, on April 13, 1598. . . . In 1589 King Henry of Navarre, leader of the French Huguenots (Protestants), had become King Henry IV of France when Henry III was murdered, leaving no direct heir. . . . opposing him was the powerful Catholic League, backed by Philip II of Spain. . . Declaring that 'Paris vaut bien une messe' ('Paris is well worth a Mass'), Henry permanently renounced Protestantism. The next year he was king. By 1598, the Catholic League was defeated. Henry confirmed Roman Catholicism as the state church while giving some religious liberties to Protestants. They were allowed to worship in public in twenty designated 'free' cities, were granted full civil rights, had their pastors paid by the state, and could keep certain strongholds, such as La Rochelle, as places of safety." [Furtado: 1001 Days]