Polish, and recognizing that his kingdom now had Polish inhabitants, Frederick also advised his successors to learn Polish. However, German was to be the language of education. The introduction of compulsory Prussian military service would also Germanize the Poles. And, the rural Poles were be mixed with German neighbors so these Poles could learn "industriousness", "cleanliness, and orderliness" and acquire a "Prussian character". By such means, Frederick boasted he would "gradually...get rid of all Poles". The Second Partition In the Second Partition of Poland in 1793, the Kingdom of Prussia annexed Gdańsk (Danzig) and Toruń (Thorn), part of the Crown of Poland since 1457. The incursion sparked the first Greater Poland Uprising in Kujawy under Jan Henryk Dąbrowski. The revolt ended after General Tadeusz Kościuszko was captured by the Russians. The Third Partition The subsequent third partitioning of 1795 marked the Prussian annexation of Podlasie region, with the remainder of Masovia, and the capital city of Warsaw (handed over to the Russians twenty years later by Frederick III). The second Greater Poland Uprising against Prussian forces (also under General Dąbrowski) broke out in Wielkopolska (Greater Poland) in 1806, ahead of the Prussian total defeat by Napoleon who created the Duchy of Warsaw in 1807. However, the fall of Napoleon during his Russian Campaign lead to the dismantling of the Duchy at the Congress of Vienna (1815) and the return of Prussian control. The third Greater Poland Uprising under Ludwik Mierosławski occurred in 1846. The Uprising was designed to be part of a general uprising against all three states that had partitioned Poland. Some 254 insurgents were charged with high treason in Berlin. Two years later, during the Spring of Nations, the fourth Polish uprising broke out in and around Poznań in 1846, led by the Polish National Committee. The Prussian army pacified the area and 1,500 Poles were imprisoned in Poznań Citadel. The Uprising showed to Polish insurgents that there was no possibility whatsoever to try to negotiate Polish statehood with the Germans. Only sixty years later, the Greater Poland Uprising (1918–1919) in the Prussian Partition helped Poland regain its freedom in the aftermath of World War I. Society Poles in the Prussian partition were subject to extensive Germanization policies (Kulturkampf, Hakata). Frederick the Great brought 300,000 colonists to territories he conquered to facilitate Germanization. That policy, however, had an opposite effect to that which the German leadership had expected: