This monograph is devoted to the study of book and written culture of the 11th-16th centuries, as well as the development of new methods for studying the surviving written monuments of Ancient Russia. The study is based on a fundamentally new methodological base, the basis of which is an integrated approach to sources of different types and varieties, a combination of methods of textual, paleographic, codicological and diplomatic analysis. The book analyzes the oldest sources on the history of Russian book and written culture, introduces new data on the political, socio-economic and socio-cultural history of Russia of the 11th-16th centuries.