From the few Polish aristocratic houses that had settled in Bohemia in the early modern period, two took turns in holding the pledge domain of Roudnice nad Labem (Raudnitz an der Elbe). First, in 1543, the domain was bought by Count Jan Tarnovský|Tarnowski for his son Jan Kryštof, and when the said son died in 1567, it was inherited by his nephew, Prince Jan Ostrožský|Ostrogski.
After ten years it was recovered from him by the South Bohemian magnate, William of Rožmberk|Rosenberg. The study deals in more detail with the legal questions of the possession of the Roudnice domain, the condition of which was, among other things, the conferral of the Bohemian right of residence (inkolat) on Tarnovský and Ostrožský, as well as on Jan Nický|Nicki, to whom the management of the Roudnice domain was entrusted in the 1570s.