Nikolay Ivanovich Kostomarov (May 16, 1817, vil. Yurasovka, Voronezh Governorate, Russian Empire – April 19, 1885, Saint Petersburg, Russian Empire) was one of the most distinguished Russian historians, a Professor of History at the Kiev University and later at the St. Petersburg University, an author of many books, including his famous biography of the seventeenth century Hetman of Zaporozhian Cossacks Bohdan Khmelnytsky, and his fundamental 3-volume Russian History in Biographies of its main figures (Russkaya istoriya v zhizneopisaniyakh yeyo glavneyshikh deyateley). Nikolay Kostomarov was so important for Ukrainian culture, that some researchers observe him as a Ukrainian historian, as well as Russian.