This is a rare edition of the book “Research on the Dvina Letters of the XV Century”, written by the famous Russian philologist A. A. Shakhmatov. The book was published in 1903 in St. Petersburg by the Department of Russian Language and Literature of the Imperial Academy of Sciences. Features and value of the publication: Rareness: A. A. Shakhmatov’s studies of ancient Russian letters are fundamental works in the field of historical linguistics and paleography. Historical significance: The Dvina Letters of the 15th century are a unique source on the history of the Russian language and the legal system of Northern Russia. Collectibles: An excellent copy for collectors of pre-revolutionary Russian scientific literature and specialists in Russian philology. Significance and contribution: The work of Shakhmatov is an important source for the study of the Old Russian language, paleography and the history of the law of Northern Russia. The Dvina Letters of the 15th century are valuable documents reflecting the legal practice and linguistic features of that time. Shakhmatov conducted a detailed analysis of these documents, which allowed a deeper understanding of the development of the Russian language and the legal system. Availability: The original 1903 edition is a bibliographic rarity and of interest to collectors and researchers.