DU PLESSIS MORNAY, PHILIPPE. – Calvinist writer, b. at Buhy in the Vexin on 5 November 1549, d. at La Forêt-sur-Sèvre on 11 November 1623. Attracted toward Calvinism from an early age, he placed the resources of a brilliant intellect and, above all, an extraordinarily intense activity at the service of heresy, earning him the title of “pope of the Huguenots.” The painful episode of the night of St Bartholomew prompted him to publish under the pseudonym Brutus Stephanus Iunius the important work Vindiciae contra tyrannos, Edinburgh 1579 (although this authorship has not yet been established by criticism), from which the Huguenots derived polemical weapons for defending the right of rebellion. Through his skill he succeeded in winning the confidence of Henry IV, king of Navarre, who appointed him his counsellor. He exploited this position to the advantage of his fellow believers, urging the king to promulgate the Edict of Nantes (1598).
The publication of one of his works on the Eucharist, De l'institution, usage et doctrine de l'Eucharistie en Eglise ancienne, comment, quand et par quels degrez la Messe s'est introduite à sa place (La Rochelle 1598), rekindled the struggle with the Catholics with great intensity; they found their defender in the bishop of Evreux, Jacques Davy Du Perron. D. P. had cited abundant material in support of his thesis, nearly 5,000 quotations drawn from the Fathers and ecclesiastical writers with evident haste and without even the most elementary criticism. It was easy for Du Perron to accuse D. P. before public opinion of incompetence and bad faith; stung to the quick, D. P. demanded a public disputation. The matter exceeded the limits of a simple polemic; the renown of the two figures created an unusual expectation among the public. Henry IV, who had meanwhile become a Catholic and was openly favouring the return of the Calvinists to the Church, readily agreed that the dispute should take place at Fontainebleau, entrusting the presidency to Bellièvre and appointing two Catholics and two Calvinists as arbiters. D. P. initially tried to postpone the meeting; then, compelled by circumstances to engage in the debate, he defended himself so feebly that Du Perron achieved an easy triumph. D. P., however, wished to defend himself and presented the Fontainebleau meeting in a quite different light in the Discours véritable de la conférence tenue a Fontainebleau (Paris, Sedan, La Rochelle, Montauban 1600), which not only failed to restore him to favour but harmed him further, because his opponent felt compelled to make the proceedings of the meeting public: Actes de la conférence tenue a Fontainebleau (Evreux 1601). Irritated, D. P. attempted to reopen the debate by publishing a Réponse au livre publié par le sieur Évesque d'Evreux (Saumur 1602), but by then his prestige had been compromised. Nor did his other work, published about ten years later, help him: Le mystère d'inquiète (there 1611), filled with poisonous attacks against the Pope, whom he presented as a usurper of authority. He also wrote four volumes of Mémoires, published posthumously, the first two at La Forêt in 1624–25 and the other two at Amsterdam in 1652–53. All his works are on the Index (decrees of 31 May 1629 and 11 September 1629).