The monograph is an academic study on Shaykhism that uses primary sources to systematically present the teachings of this mystical school of Shi‘ism. The school originated and developed rapidly at the end of the 18th and the first half of the 19th centuries in the Near and Middle East. The book contains biographies of the founders of Shaykhism and issues relating to their sharp polemics with their opponents. It examines the fundamental principles of Shaykhi teaching with a special focus on its four pillars, and introduces important works of the school’s theorists.The monograph is supplemented with an extensive set of scanned pages of Shaykhi manuscripts from the collection of the Institute of Oriental Manuscripts of the Russian Academy of Sciences (IOM RAS).