イーゴリ公
Russian composers also wrote operas based on historical figures, including "Boris Godunov" by Modest Mussorgsky (1839–1881), which was composed between 1868 and 1873, and is considered his masterpiece. Its subjects are the Russian ruler Boris Godunov, who reigned as Tsar (1598 to 1605). Equally famous is Alexander Borodin's "Prince Igor", the libretto for which the composer developed from the Ancient Russian epic "The Lay of Igor's Host", which recounts the campaign of Rus prince Igor Svyatoslavich against the invading Cuman ("Polovtsian") tribes in 1185.