Drang nach Osten
Because the Recovered Territories had been under German and Prussian rule for many centuries, many events of this history were perceived as part of "foreign" rather than "local" history in post-war Poland. Polish scholars thus concentrated on the Polish aspects of the territories: medieval Piast history of the region, the cultural, political and economic bonds to Poland, the history of the Polish-speaking population in Prussia and the "Drang nach Osten" as a historical constant since the Middle Ages.