The Prussian hold on Polish areas was somewhat weakened after 1807 where parts of its partition were restored to Duchy of Warsaw.[1] The power status of Prussia was dependent on hindering any form of Polish statehood, due to crucial position of Wielkopolska, Silesia and Pomeranian-all areas inhabited either by Polish majority or substantial Polish population; it didn't support Polish attempts at restoration of Poland during Congress of Vienna, where Prussia tried to gain Duchy of Warsaw or at least its western provinces.[3] In 1815 the Prussian king made several guarantees in his speech to Poles in the newly formed Grand Duchy of Posen (created out of territories of Duchy of Warsaw) in regards to rights of Polish language and cultural institutions.[3] In order to ensure loyalty of the newly re-conquered territories the Prussians engaged in several propaganda gestures hoping they would be enough to gain land-owners and aristocracy support.[6]