The end of the Second World War brought a new legal, political and spatial order to the territory of former East Prussia. The political, demographic and economic area was divided between Poland and the Soviet Union as a result of the decision made between the world powers. Both sides of the border carried out separate policies to respect the German heritage of these lands and changes made to the names of towns and geographic sites. These two approaches affected and continue to influence the current identity and historical consciousness of the inhabitants of the Warmia and Mazury Region and Kaliningrad Region of the Russian Federation. The aim of the article is to establish a comparison of this kind of historical policies related to the German heritage of these lands, and the processes of evolution of the identity and historical awareness of both communities, as well as to study the processes of the evolution of identity and historical awareness in the Warmia and Mazury and Kaliningrad Regions. The following selected issues related to identity and historical consciousness are analysed: history of the former German sacral and defensive architecture, museum collections and monuments; the state of preservation of pre-war names of rural, urban and geographical areas; the currently observed frequency of recourse to German resentments in the society, culture and economy. One of the currently observed processes around the Polish-Russian border are the transitions of identity and awareness resulting from the cross-border cooperation of local communities.