Prince of the Imperial Blood Igor Konstantinovich of Russia was the sixth child of Grand Duke Constantine Constantinovich of Russia by his wife Elisaveta Mavrikievna née Princess Elisabeth of Saxe-Alt
Igor in the uniform of His Majesty’s Hussar Life Guards Regiment, 1913.
Prince John Konstantinovich of Russia, formerly Grand Duke John Konstantinovich of Russia, sometimes also known as Prince Ivan, Prince Ioann or Prince Johan, was the eldest son of Grand Duke Konstanti
Prince Ioann Konstantinovich of Russia in his military uniform of the Imperial Russian Army (1913)
