He sounds pretty incredible as a person and scholar. He did have 9 children. As he and his family lived around the time of the Russian Revolution the fate of many of his immediate family was very sad.
"KR was both a patron of Russian art and an artist in his own right. A talented pianist, the Grand Duke was Chairman of the Russian Musical Society, and counted Tchaikovsky among his closest friends. But KR was first and foremost a man of letters. He founded several Russian literary societies. He translated foreign works (including Schiller and Goethe) into Russian, and was particularly proud of his Russian translation of Hamlet. An accomplished poet and playwright, KR also took great interest in the direction of his plays. The Grand Duke actually appeared in his last play, "King of Judea," playing the role of Joseph of Arimathea.
The Grand Duke's artistic slavophilism and devotion to duty endeared him to both Alexander III and Nicholas II. The former appointed KR as President of the Russian Academy of Sciences, and later as Chief of All Military Colleges. He was also made an honorary member of the Royal Swedish Academy of Sciences in 1902, with reference to his chairmanship of a Swedish-Russian surveying commission.
KR and his wife were among the relatively few Romanovs on intimate terms with Nicholas II and the Empress Alexandra, who found KR's devotion to his family a welcome respite from the playboy lifestyle of many of the other Grand Dukes.
He was also a close friend of the Grand Duchess Elizabeth and wrote a poem about her expressing his admiration when she first came to Russia to be married. He was also one of the few members of the Imperial Family to go to Moscow to attend the funeral of Elizabeth's husband, Grand Duke Sergei Alexandrovich, who was killed by a terrorist's bomb."