In the beginning of 1559 the health of Queen Isabella began to fail, and Melchior Balassa, a great Transylvanian noble, wrote to Ferdinand proposing, on her death, to place Transylvania in his hands. This letter was intercepted, and sent to Isabella, who, having such a proof of the treachery of one of her most trusted adherents, thought it advisable to open negotiations with Ferdinand herself, and, with the Sultan’s approval, did so through her brother the King of Poland. It was proposed that one of Ferdinand’s daughters should marry John Sigismund, and that the latter should have Transylvania and Lower Hungary (the north-eastern part of Hungary, between Poland and Transylvania), but should abandon the title of King. These negotiations were broken off by her death, which took place at Karlsburg in September, and an attempt in the following year to renew them also came to nothing, as John Sigismund refused to renounce the title of King. In the winter of 1561 Andrew Bathory persuaded his brother Nicholas and Melchior Balassa to go over to Ferdinand’s side.[292] As soon as Ferdinand had recovered the town of Munkats, Balassa was to receive it for his life, with the right of maintaining a certain number of soldiers at Ferdinand’s expense, and, in return, to give up to Ferdinand various towns immediately to the north of Transylvania Proper, which were his possession. Roostem died in July 1561, and was succeeded by Ali, who proved much more pliant in his negotiations with Busbecq, and the latter at last succeeded in obtaining a peace for eight years. The principal stipulations of the treaty were as follows:[293] 1. Ferdinand to pay an annual tribute of 30,000 ducats, and also the arrears due in respect of the last two years. 2. The Sultan engaged not to attack Ferdinand either directly, or by furnishing assistance to John Sigismund. He also undertook that John Sigismund should respect the territories of Ferdinand. 3. Melchior Balassa and Nicholas Bathory, and others in a similar position, who had returned to their allegiance to Ferdinand, to be included in the peace with their property and lordships, and to be the vassals of Ferdinand and John Sigismund conjointly. 4. If any of Ferdinand’s subjects had been expelled from his property by the adherents of John Sigismund, or _vice versâ_, no suits or proceedings to recover such property to be taken during the peace. 5. If new and otherwise irreconcilable differences should arise between the contracting parties with regard to the limits of their jurisdiction, as a provisional arrangement the _de facto_ subjects of each party at the commencement of the peace to remain so during its continuance, and, in particular, certain villages near the Danube and the fortress of Tata, some of which were in Ferdinand’s and some in the Sultan’s possession, to remain respectively as they were, and those in Ferdinand’s possession not to be molested by the garrison of Tata.