from what Ferdinand regarded as a more pernicious form of heresy than Lutheranism, and also from the clutches of the rival House of Wittelsbach. The way for this conversion was prepared by the Wittenberg Concord of 1536. The hostility between the Zwinglian and Lutheran sects had to some extent subsided since Zwingli's death. Melanchthon had modified his attitude towards predestination, and had been much impressed by Oecolampadius' treatise on the use of the Eucharist during the first three centuries. Luther even brought himself to entertain a friendly feeling for Zwingli's successor Bullinger. After various preliminary negotiations, in which Bucer was as usual the leading spirit, a conference between Luther and representatives of the modified Zwinglianism which prevailed in the cities of Upper Germany was held in Luther's house at Wittenberg in May, 1536. The two parties agreed on a form of words which covered their differences about the real presence in the Eucharist; they were not so successful with regard to the other disputed point, the reception of the body of Christ by unworthy communicants, but they agreed to differ. Luther expressed himself willing to bury the past and roll the stone upon it, and extended to Bucer and the Upper German cities that "brotherly love" which he had refused to Zwingli at Marburg in 1529.
The Concord of Wittenberg only stopped for a while the rifts which had begun to appear in the Schmalkaldic Union. The mere fact of security would have tended to relax the bonds, and there were personal as well as religious differences between John Frederick and Philip of Hesse. Philip expressed contempt for the dull but honest Elector, while John Frederick had grave doubts about Philip's orthodoxy and the morality of his policy. Philip had always inclined to Zwinglian views and resented dictation from Wittenberg; and the two religious parties had nearly come to an open breach over the reformation of Württemberg. Ulrich himself was more Zwinglian than Lutheran, and his duchy was partitioned into two spheres of influence, in one of which the Lutheran Schnepf laboured and in the other the Zwinglian Blarer. The latter proved the stronger, and in 1537 Blarer procured the abolition of images in spite of the opposition of Schnepf and Brenz, while Ulrich devoted the confiscated Church revenues to exclusively secular purposes. It seemed as though Hesse, Württemberg, and the Oberland cities might form a strong Zwinglian Union independent of the Lutheran League of Schmalkalden. Both the Elector and the Landgrave were hesitating whether to renew that League, and both were pursuing independent negotiations at the Court of Vienna, where Ferdinand by his conciliatory demeanour and concessions induced them both to turn a deaf ear to the persuasions of the Habsburgs' foreign enemies.
The necessity for this pacific diplomacy on Ferdinand's part was amply demonstrated by the course of the war with the French and the Turks from 1536 to 1538. In spite of the neutrality of Henry VIII
