Louis was also on his guard against religious dissent. Like most of his contemporaries, he believed that toleration was no virtue and that unity in the state was extremely difficult to maintain where two or more churches were tolerated. The same fervour that had contributed to the revival of Catholic devotion after 1600 led church spokesmen to urge the king to promote conversions and to end the scandal of legal protection for heretics. By 1678 Louis, persuaded that most Protestants had already returned to the true faith, intensified the persecution of Protestants; churches were destroyed, certain professions were put out of reach of the Huguenots, and Protestant children were taken away from their parents and brought up as Roman Catholics. The notorious practice of dragonnades, the billeting of soldiers in Protestant homes with permission to behave as brutally as they wished, was introduced. Finally, in 1685, the Edict of Nantes was revoked so that Louis could claim that he had succeeded where Emperor Leopold I had failed—that is, in extirpating Protestantism from his realm.

French Catholics welcomed the revocation of the Edict of Nantes, but the decision angered Protestant Europe at a time when Louis’s European designs were beginning to meet serious resistance. The revocation deprived France of a number of gifted craftsmen, sailors, and soldiers. At least 600 officers, including Marshal Frederick, Herzog (duke) von Schomberg, and Henri de Massue, marquis de Ruvigny (later the earl of Galway), joined William of Orange, the leader of the Grand Alliance against Louis. Research, however, has reversed the earlier view that the decay of French industry at the end of Louis’s reign was the direct result of the expulsion of Huguenot mercantile talent.

The same zeal for uniformity made Louis attack the Jansenists. The theological position of the Jansenists is difficult to define; but Louis, who was no theologian, was content with the simple fact that these zealous Catholics had taken up an unorthodox position that threatened the unity of the state. The movement had begun over the perennial issue of grace and free will as it was propounded in the Augustinus of Bishop Cornelius Otto Jansen, published in 1640. In 1653 Pope Innocent X condemned five propositions from Jansen’s doctrine, but the movement grew in strength with notable adherents, including Jean-François-Paul de Gondi, cardinal de Retz, and the great mathematician Blaise Pascal. In 1705 Pope Clement XI published the bull Vineam Domini (“Vineyard of the Lord”), which further condemned the writings of Jansen; but the archbishop of Paris, Louis-Antoine, cardinal de Noailles, appeared ready to lead the Jansenist forces in opposition to the pope. Under the influence of his confessor, Père Michel Le Tellier, Louis decided to ask the pope for another formal condemnation of the creed. Finally, in 1713, the famous bull Unigenitus (“Only Begotten Son”) was promulgated but, far from ending Jansenism, drove it into a disruptive alliance with Gallicanism during the following reign. Louis’s real attitude in this situation is not entirely clear: certainly his policy was in keeping with his authoritarian insistence upon unity. He was suspicious of religious innovation, and his action was consistent with the increasingly orthodox and rigid mood of his last years. Yet, in seeking the pope’s support in this matter, he was reversing years of bitter hostility toward Rome—years when, like many of his predecessors, including Francis I and Henry IV, he had leaned heavily upon the traditional Gallican doctrine.

According to that doctrine, the French king possessed the right of temporal and spiritual régale—that is, the right to nominate new bishops and to administer and draw the revenue from bishoprics while they remained vacant. In 1673, despite papal opposition, Louis extended this right to the whole of the French kingdom, which had been enlarged in the recent War of Devolution (1667–68). Eventually, in 1682, the Four Gallican Articles were published as a law of the French state, asserting that the king was in no way subject to the pope in temporal matters and could not be excommunicated and reaffirming the independence of the French church from Rome. The mutual animosity of king and pope ended only in 1693, when Louis agreed to suspend the edict of 1682; but it was a suspension only, not a recantation. The tradition of Gallican independence remained.