“Collection of Works of Equal-to-the-Apostles Nicholas of Japan” as a source on the History of Orthodoxy in the Far East

The article is devoted to the research and publishing project for the publication of the ten-volume edition of the “Collection of Works of Equal-to-the-Apostles Nicholas of Japan”. This project is being implemented by the Nikolo-Ugreshskaya Theological Seminary with the support of the Department for External Church Relations of the Russian Orthodox Church and in cooperation with the Russian State Historical Archive. In 2018, the first two volumes were published, united by the common title «Official Correspondence». The following year, the next volume was published under the title «Letters». The fourth volume opens the publication of the diaries of the Equalto- the-Apostles Nicholas of Japan. The article gives a brief description of the materials included in the first four volumes. Based on the analysis of the documents, it is concluded that they are the most valuable source of information, absolutely reliable and objective, allowing for a deep study of the history of Japanese Orthodoxy.