Grand Duke Konstantin Konstantinovich of Russia was a grandson of Emperor Nicholas I of Russia, and a poet and playwright of some renown. He wrote under the pen name "K.R.", initials of his given name and family name, Konstantin Romanov. Wikipedia
Born: August 22, 1858, Strelna, Saint Petersburg, Russia
Died: June 15, 1915 (age 56 years), Pavlovsk Museum, Saint Petersburg, Russia
Spouse: Princess Elisabeth of Saxe-Altenburg (m. 1884–1915)
Siblings: Olga Constantinovna of Russia