In the meanwhile French diplomacy continued actively. Francis I was disturbed by the result of the invasion of Hungary which he had himself urged, for the kingdoms of Hungary and Bohemia seemed now to be falling into the hands of his enemies of Austria. More than ever he had need of the Ottoman alliance, and he determined on an alliance with Zapolya. He sent Rincon to the latter to form an offensive and defensive alliance, claiming as his reward the reversion of the kingdom of Hungary for his second son, Henry, should Zapolya die without heirs.[106] On the 20th of September, 1528, Sultan Suleiman renewed a former act called by old French historians “la trêve marchande,”[107] giving commercial privileges to the Catalonian and French merchants in the Mediterranean, and placing all French factories, consuls, and pilgrims, under the protection of the Sublime Porte. The French were thus able to reappear with confidence in the Levant, and were welcomed by the Christians in the East. The pilgrimages to Jerusalem recommenced. Even Francis expressed a desire to go to the Holy Land and to visit en route “his dear patron and friend, Suleiman.”[108] A question concerning the Holy Places in Palestine was also brought up by Francis at this time, which is of very great significance, as it marks the beginning of the train of developments that resulted in the conception of the protection of Turkey’s Christian subjects by the European Powers. Francis and Venice united in asking that a certain church in Jerusalem, long before converted into a mosque, be restored to the Christians.[109] Ibrahim replied that had the King of France demanded a province, the Turks would not have refused him, but in a matter of religion they could not gratify his desire. Nevertheless the Sultan made the following general promise which was later used as a basis for further demand by the Catholics. He wrote to Francis:[110] “The Christians shall live peaceably under the wing of our protection; they shall be allowed to repair their doors and windows; they shall preserve in all safety their oratories and establishments which they actually occupy, without any one being allowed to oppose or torment them.”[111] On the 10th day of May, 1529, Suleiman set out to settle matters by force with Charles V. Before the end of August the Turks were again encamped with a vast army on the fatal plain of Mohacz. Here John Zapolya met his overlord and did him homage. Three days later the Turks advanced to Buda, and took it from Ferdinand, crowning Zapolya a second time within the walls of the capital. By September 27, Suleiman was encamped before Vienna.