The Rosenbergs were the members of a very powerful group of families called the Vítkovici, who were the practical rulers of the south and south-east of Bohemia. There they exercised an authority which was little short of regal. They had bodies of soldiers at their command; they coined money and built fortresses at their pleasure. They professed to trace their origin to the Italian family of the Orsini; and they had played almost as important a part in the thirteenth century as the Vrs̆ovici had played in the earlier history of Bohemia. Of these Vítkovici the Rosenbergs were the most important branch; and their name shows that they had to a large extent Germanised themselves, even in the time of Ottakar. They had strengthened their position in Bohemia by founding towns and monasteries, planting woods, and building churches; and their fishponds became so important that the town of Prague was mainly supplied from them. So deeply-rooted was their power that the signs of its past greatness are visible even at the present day, in the towns of Krumov, Tr̆ebon̆, Prachatice, the monastery of Hohenfurt, and the castle and village of Rosenberg. It will easily be understood that the leader of so powerful a clan would deeply resent such attempts as those of Wenceslaus to infringe the privileges of the nobility, and to call men of lower rank to his Councils. Nor did the nobles rely solely on Bohemian support. Jodok of Moravia had taken counsel with the Duke of Austria and the Margrave of Meissen, who were always ready for any opportunity of weakening the Bohemian kingdom. Such a combination as this would have been dangerous even to Charles; and Wenceslaus was quite unable to stand against it.
The rebels were quickly ready for action; and in the year 1394, as Wenceslaus was on his way to Prague, he was seized by Jodok and his followers, and imprisoned in the Castle of Prague. The demands of the insurgent nobles were now formulated. They insisted that Wenceslaus should leave them in possession of all the fortresses that had been pledged to them, and that he should appoint Jodok as his Viceroy in Bohemia. Duke John of Görlitz, the youngest brother of Wenceslaus, hastened to the rescue of the king; and, though Jodok succeeded in carrying off his prisoner to Austria, John was welcomed by the citizens of Prague, who swore to recognise him as the administrator of the country till the King should once more be at liberty to act.