بروسيا الملكية
Under Polish sovereignty, Prussians, particularly those from Royal Prussia, saw their liberties confirmed and expanded; local cities prospered economically (Gdańsk become the largest and richest city in the Commonwealth), and local nobility participated in the benefits of Golden Liberty, such as the right to elect the king. Royal Prussia, as a direct part of the Kingdom of Poland (and later Polish–Lithuanian Commonwealth) had more influence on Polish politics and more privileges than Ducal Prussia, which remained a fief (for example, while nobles from the Royal Prussia had their own sejmiks, Sejm and Senate representatives, those from the Duchy did not). Royal Prussia also had its own parliament, the Prussian "Landesrat", although it was partially incorporated into the Commonwealth Sejm after the Union of Lublin, it retained distinct features of Royal Prussia.