A few days after Christmas 1188, Frederick received Hungarian, Byzantine, Serbian, Seljuk and possibly Ayyubid envoys in Nuremberg. The Hungarians and Seljuks promised provisions and safe-conduct to the crusaders. The envoys of Stefan Nemanja, grand prince of Serbia, announced that their prince would receive Frederick in Niš. An agreement was reached with the Byzantine envoy, John Kamateros, but it required Godfrey of Würzburg, Frederick of Swabia and Leopold of Austria to swear oaths for the crusaders' good behaviour. Bishop Hermann of Münster, Count Rupert III of Nassau, the future Henry III of Dietz and the imperial chamberlain Markward von Neuenburg with a large entourage were sent ahead to make preparations in Byzantium.