The genealogy of the Rurikovich and Gediminovich is important for the study of Russian political history. The reference book covers all the lines of the Rurikovich and Gediminovich dynasties until their representatives lose their specific rights and the disintegration of the dynasties into separate princely families. Justifications, information about marriages and tables that each prince occupied are submitted to genealogical tables. The directory has alphabetical index keys to the tables. Designed for historians and everyone who is interested in the political history of the IX-XVI centuries.