Władysław-Jogaila gathered his troops on the Polish-Hungarian border, but , Palatine of Hungary, and , Archbishop of Esztergom, stopped his invasion of Hungary. In September, Konrad von Jungingen told the prince-electors of the Holy Roman Empire that the union of Poland, Lithuania and Hungary under Władysław-Jogaila's rule would endanger Christendom. However, most of Sigismund's opponents, who were especially numerous in Croatia, supported the claim of Ladislaus of Naples, the last male member of the Capetian House of Anjou. On 8 September, the most influential Hungarian lords declared that they would not support any change in government while Sigismund was far from Hungary fighting against the Ottoman Turks. Before the end of the year, peace negotiations between the representatives of Hungary and Poland ended with an agreement. Jadwiga adopted the title "heir to Hungary", but she and her husband took no further action against Sigismund. The relationship between Lithuania and the Teutonic Knights remained tense. Jadwiga and her Polish advisers invited the Grand Master, Konrad von Jungingen, to Poland to open new negotiations in June 1396. Conflicts with Vladislaus of Opole and Siemowit of Masovia, who had not given up their claims to parts of Ruthenia and Cuyavia, also intensified. To demonstrate that the territories were under Jadwiga's direct control, Władysław-Jogaila granted the Duchy of Belz (in Ruthenia) and Cuyavia to her in early 1397. However, Jadwiga and her Polish advisers wanted to avoid a war with the Teutonic Order. In response, Władysław-Jogaila replaced most Polish "starostas" (aldermen) in Ruthenia with local Orthodox noblemen. According to German sources, Władysław-Jogaila and Vytautas jointly asked Pope Boniface IX to sanction Vytautas' coronation as king of Lithuania and Ruthenia. Jadwiga and Jungingen met in Włocławek in the middle of June, but they did not reach a compromise. The Teutonic Order entrusted Vladislaus of Opole with the task of representing their claims to Dobrzyń against Jadwiga. Jadwiga and her husband met Sigismund of Hungary, who had returned there after his catastrophic defeat in the Battle of Nicopolis, on 14 July.