Ioann Konstantinovich was born in Pavlovsk Palace, as a Grand Duke of Russia with the style Imperial Highness, but at the age of 9 days, an Ukaz of his cousin Emperor Alexander III of Russia stripped him of that title, as the Ukaz amended the House Law by limiting the grand-ducal title to grandsons of a reigning emperor.

He once entertained the possibility of becoming an Orthodox monk, but eventually fell in love with Princess Helen of Serbia, the daughter of King Peter I of Serbia and his wife Princess Zorka of Montenegro, niece of Grand Duchess Militza, Grand Duchess Anastasia of Russia and Queen Elena of Italy.

As a daughter of the reigning King, after the marriage, she retained her style of Royal Highness and as such she had the right to receive foreign diplomats in her own right, unlike her husband.

[1][2][3] His body was eventually buried in Beijing, in the cemetery of the Russian Orthodox Mission, which was destroyed in 1986 to build a park.

His sister Princess Vera Konstantinovna, the youngest daughter of Grand Duke Konstantin Konstantinovich, died in New York in 2001, aged 94.