Berlin is the capital and the largest city of Germany, as well as one of its 16 constituent states.
Dębogórze (Eichenberg, Dãbògòrzé) is a village in the administrative district of Gmina Kosakowo, within Puck County, Pomeranian Voivodeship, in northern Poland.
German Eastern Marches Society (Deutscher Ostmarkenverein, also known in German as Verein zur Förderung des Deutschtums in den Ostmarken) was a German radical,Geoff Eley, op.cit., extremely nationalist xenophobic organization founded in 1894.
Prussia (Preußen) was a historically prominent German state that originated in 1525 with a duchy centred on the region of Prussia.
Witold Jakóbczyk (1909–1986) was a Polish historian and professor at Poznań University, specializing in the history of Greater Poland in the 19th century.