All this was but the prelude to greater changes. In the Electoral Congress held at Muehlhausen, the Roman Catholics had demanded of the Emperor that all the archbishoprics, bishoprics, mediate and immediate, abbacies and monasteries, which, since the Diet of Augsburg, had been secularized by the Protestants, should be restored to the church, in order to indemnify them for the losses and sufferings in the war. To a Roman Catholic prince so zealous as Ferdinand was, such a hint was not likely to be neglected; but he still thought it would be premature to arouse the whole Protestants of Germany by so decisive a step. Not a single Protestant prince but would be deprived, by this revocation of the religious foundations, of a part of his lands; for where these revenues had not actually been diverted to secular purposes they had been made over to the Protestant church. To this source, many princes owed the chief part of their revenues and importance. All, without exception, would be irritated by this demand for restoration. The religious treaty did not expressly deny their right to these chapters, although it did not allow it. But a possession which had now been held for nearly a century, the silence of four preceding emperors, and the law of equity, which gave them an equal right with the Roman Catholics to the foundations of their common ancestors, might be strongly pleaded by them as a valid title. Besides the actual loss of power and authority, which the surrender of these foundations would occasion, besides the inevitable confusion which would necessarily attend it, one important disadvantage to which it would lead, was, that the restoration of the Roman Catholic bishops would increase the strength of that party in the Diet by so many additional votes. Such grievous sacrifices likely to fall on the Protestants, made the Emperor apprehensive of a formidable opposition; and until the military ardour should have cooled in Germany, he had no wish to provoke a party formidable by its union, and which in the Elector of Saxony had a powerful leader. He resolved, therefore, to try the experiment at first on a small scale, in order to ascertain how it was likely to succeed on a larger one. Accordingly, some of the free cities in Upper Germany, and the Duke of Wirtemberg, received orders to surrender to the Roman Catholics several of the confiscated chapters.