Andrey Vasilievich Ekzemplyarsky - Russian historian, successfully graduated from the historical and philological faculty of St. Petersburg University. As a student, under the leadership of K.H. Bestuzhev-Ryumin worked with Polish sources on the history of the Time of Troubles. He was a teacher in the gymnasiums of Poland, in Yekaterinburg and Perm. He took part in the work on the Brockhaus and Euphron Encyclopedic Dictionary. The study "The Great and Specific Princes of Northern Russia in the Tatar Period" is the most authoritative source about the life and work of Russian princes of the period of feudal fragmentation. The book contains biographies of the Grand Dukes of Vladimir and Vladimir-Moscow, who lived and acted in the Tatar period of Russian history.