This publication highlights little-studied problems of Polish history during the “thaw” and “developed socialism” period (1956–1980). Using a large array of documents from Polish and Russian archives, the author introduces the reader to facts and events that had a huge impact on the worldview of modern Poles, but remain little known outside the country. The book, the fruit of many years of research into the history of Poland in the second half of the 20th century, includes works published in different years in scientific periodicals. Article “Zionists and the Party. On the role of anti-Semitism in the struggle of factions within the Polish United Workers' Party" is published for the first time.