9 Jun 1815 - 5 Dec 1848. 1815–1830. According to the Congress of Vienna, parts of the Prussian territory partitioned from Poland were passed on to Russia. From the remainder the Grand Duchy of Posen was to be created, that was to be a nominally autonomous province under Hohenzollern rule with the rights of "free development of Polish nation, culture and language", and was outside the German Confederation. Originally the Grand Duchy was to include Chelmno and Torun. Prussia however disregarded. At this time the city of Poznan was the administrative centre.