The monograph by a German historian, published for the first time in Russian translation, provides an overview and analysis of various conspiracy theories that periodically arose in various European countries (France, Italy) from the end of the 18th century to the mid-20th century (from the Great French Revolution to National Socialism) , England, Germany, Russia). The main types of such theories are identified, in which, depending on the era and social situation, enlightenment philosophers, Illuminati, Freemasons, liberals, socialists, and Jews could act as conspirators. The role of conspiracy theories in the genesis of conservative Christian thought and radical political movements is examined. Of particular value is the extensive bibliography, which includes rare publications in different languages. The book can be addressed to historians, sociologists, and political scientists, but it also has an undeniable social resonance.