In October 1685, Louis XIV, the grandson of Henry IV, renounced the Edict and declared Protestantism illegal with the Edict of Fontainebleau. This act, commonly called the '"revocation of the Edict of Nantes",' had very damaging results for France. While the wars of religion did not re-ignite, intense persecution of Protestants took place. All Protestant ministers were given two weeks to leave the country unless they converted to Catholicism and all other Protestants were prohibited from leaving the country. In spite of the prohibition, the renewed persecution - including many examples of torture - caused as many as 400,000 to flee France at risk of their lives. Most moved to Great Britain, Prussia, the Dutch Republic, Switzerland, South Africa and the new French colonies and the Thirteen Colonies in North America. Some even moved to Denmark, where the city of Fredericia, laid waste after the Swedish conquest in 1656, needed new settlers and a specific clause in the city ordinance allowed other than Lutheran-Protestants to live in the city. This exodus deprived France of many of its most skilled and industrious individuals, some of whom thenceforward aided France's rivals in the Netherlands and in England. The revocation of the Edict of Nantes also further damaged the perception of Louis XIV abroad, making the Protestant nations bordering France even more hostile to his regime. Upon the revocation of the edict, Frederick William, Elector of Brandenburg issued the Edict of Potsdam, which encouraged Protestants to come to Brandenburg-Prussia.