Grand Duke Konstantin Konstantinovich is one of the most prominent representatives of the Romanov dynasty. A poet whose works all of pre-revolutionary Russia knew by the cryptonym “K. R.”, playwright, translator, actor, artist, musician, military leader, scientist, who headed the Imperial Academy of Sciences for more than a quarter of a century, a citizen of his country... The book about the life of this outstanding man is written on documentary material. It cites the Grand Duke's diary, K.R.'s correspondence with outstanding figures of Russian culture, and memoirs of contemporaries about Konstantin Konstantinovich.