Frederick was welcomed by Stefan Nemanja in Niš with pomp on 27 July. Although the Serbian ruler sought investment with his domains from the emperor, Frederick refused on the grounds that he was on a pilgrimage and did not wish to harm Isaac. A marriage alliance was arranged between a daughter of Duke Berthold of Merania and a nephew of Nemanja, Toljen. Frederick also received messages of support from Tsar Peter II of Bulgaria, but refused an outright alliance. Despite Frederick's care not to be drawn into Balkan politics, the events at Niš were regarded by the Byzantines as hostile acts.