ENThe monograph of the well-known Polish sociologist and historian Andrzej Sakson (in 2004-2011 Director of the Western Institute in Poznan) summarises the long years of his work on the history and contemporary life of one of the most interesting regions of Eastern Europe, the former East Prussia. The study is based on a huge database of sources (archival and published documents, memoirs and diaries, the ‘verbal history’ materials and press publications) and historiography (articles and monographs in English, German, Polish and Russian are used); the data from various case studies and meaningful personal experiences of the author are processed. He is familiar with all significant publications of the Kaliningrad historians (including the articles of Yu. V. Kostyashov providing a basis for the recent ‘Secret History of the Kaliningrad region’ which A. Sakson probably did not have time to study by completion of his work). All that has created a fundamental work, the likes of which perhaps are difficult to find in the modern historiography. A. Sakson traces the history of the region during the ‘long’ twentieth century, from the end of the First World War to the present day. The goal of his research is to study the general and special aspects in the development of the territory which at the end of the Second World War was divided between the two (and after the collapse of the Soviet Union, three) states, the postwar period became a major research interest. For obvious reasons, in the characterisation of the post-war period, the greatest attention was paid to the Polish Warmia and Mazury region (about 44 % of the text), a little less, the Russian Kaliningrad region (38 %) and very little (18 %), the Klaipeda area in Lithuania. Russian readers might be interested in the first place in the ‘Kaliningrad aspect’ of that topic, the Polish scientist’s vision with regard to the past and present of the 'utmost Western' region.