Grand Duke Konstantin Konstantinovich of Russia

Grand Duke Konstantin Konstantinovich of Russia August 1858 in Strelna June 1915 in Pavlovsk was a grandson of Emperor Nicholas I of Russia, and a poet and playwright of some renown. He wrote under pen name K.R., initials of his given name and family name, Konstantin Romanov.

The fourth child of the Grand Duke Konstantin Nikolayevich of Russia and his wife Princess Alexandra of SaxeAltenburg, KR was born in the Constantine Palace, Saint Petersburg. His eldest sister Grand Duchess Olga married King George I of the Hellenes in 1867.

Source: Wikipedia