Question: When did Prince John Konstantinovich Of Russia's mother die?

Knowledge 1: Prince John Konstantinovich of Russia
Prince Ioann Konstantinovich of Russia (5 July 1886 – 18 July 1918), sometimes also known as Prince John, Prince Ivan or Prince Johan, was the eldest son of Grand Duke Konstantin Konstantinovich of Russia by his wife Yelizaveta Mavrikievna, née Princess Elisabeth of Saxe-Altenburg.He was described by contemporaries as a gentle, religious person, nicknamed "Ioannchik" by his relatives. [SEP] Knowledge 2: Princess Elisabeth of Saxe-Altenburg (1865–1927)
Elizabeth Mavrikievna ("née" Princess Elisabeth Auguste Marie Agnes of Saxe-Altenburg; 25 January 1865 – 24 March 1927) was a Russian Grand Duchess by marriage.She was the wife of Grand Duke Konstantin Konstantinovich of Russia (1858–1915), whom she married in 1884 in Saint Petersburg, Russia.
Knowledge 1: Prince John Konstantinovich of Russia
Prince Ioann Konstantinovich of Russia (5 July 1886 – 18 July 1918), sometimes also known as Prince John, Prince Ivan or Prince Johan, was the eldest son of Grand Duke Konstantin Konstantinovich of Russia by his wife Yelizaveta Mavrikievna, née Princess Elisabeth of Saxe-Altenburg.He was described by contemporaries as a gentle, religious person, nicknamed "Ioannchik" by his relatives. [SEP] Knowledge 2: Prince Constantine Constantinovich of Russia
Prince Constantine Constantinovich of Russia(" Константин Константинович"; 1 January 1891 – 18 July 1918), nicknamed Kostya by the family, was the fourth child of Grand Duke Constantine Constantinovich of Russia by his wife Grand Duchess Elizabeth Mavrikievna of Russia.The Prince was a silent, shy person who fancied theatre and was educated in the Corps des Pages, a military academy in Saint Petersburg.He served in the army during the First World War.A priest who met him at the front, Hegumen Seraphim, wrote:" He was an extremely modest officer of the Guard of the Izmaylovsky Regiment, much beloved by officers and soldiers alike; along with them he was a brave soldier who distinguished himself.I personally remember seeing him in the trenches among the soldiers, risking his life."After seeing the happiness of his two elder siblings, John and Tatiana, Konstantin was keen to start his own family.He fancied the Tsar's oldest daughter, Olga, but was also keen on Princess Elisabeth of Romania.Elisabeth's grandmother, the former Grand Duchess Maria Alexandrovna of Russia, wrote to her daughter, the Crown Princess Marie of Romania in 1911, saying," The young Kostya is seized now with terror that she will be snatched away, as he says, before he has even made her acquaintance.The young man seems really quite nice, is much liked in his regiment, and they have really been very well brought up.This one is full of life ... if you have nothing against this youth coming on a passing visit, will you telegraph to me."However, the request was denied on political grounds, as Prince John was married to Helen of Serbia, and Konstantin never did find the marriage he longed for.In March 1918 he was exiled to the Urals by the Bolsheviks and murdered in a mineshaft near Alapayevsk, along with his brothers Prince John Constantinovich and Prince Igor Konstantinovich, his cousin Prince Vladimir Pavlovich Paley and other relatives and friends.His body was eventually buried in the Russian Orthodox Church cemetery in Beijing, which was destroyed in 1986 to build a park.
Knowledge 1: Princess Elisabeth of Saxe-Altenburg (1865–1927)
Elizabeth Mavrikievna ("née" Princess Elisabeth Auguste Marie Agnes of Saxe-Altenburg; 25 January 1865 – 24 March 1927) was a Russian Grand Duchess by marriage.She was the wife of Grand Duke Konstantin Konstantinovich of Russia (1858–1915), whom she married in 1884 in Saint Petersburg, Russia. [SEP] Knowledge 2: Prince Constantine Constantinovich of Russia
Prince Constantine Constantinovich of Russia(" Константин Константинович"; 1 January 1891 – 18 July 1918), nicknamed Kostya by the family, was the fourth child of Grand Duke Constantine Constantinovich of Russia by his wife Grand Duchess Elizabeth Mavrikievna of Russia.The Prince was a silent, shy person who fancied theatre and was educated in the Corps des Pages, a military academy in Saint Petersburg.He served in the army during the First World War.A priest who met him at the front, Hegumen Seraphim, wrote:" He was an extremely modest officer of the Guard of the Izmaylovsky Regiment, much beloved by officers and soldiers alike; along with them he was a brave soldier who distinguished himself.I personally remember seeing him in the trenches among the soldiers, risking his life."After seeing the happiness of his two elder siblings, John and Tatiana, Konstantin was keen to start his own family.He fancied the Tsar's oldest daughter, Olga, but was also keen on Princess Elisabeth of Romania.Elisabeth's grandmother, the former Grand Duchess Maria Alexandrovna of Russia, wrote to her daughter, the Crown Princess Marie of Romania in 1911, saying," The young Kostya is seized now with terror that she will be snatched away, as he says, before he has even made her acquaintance.The young man seems really quite nice, is much liked in his regiment, and they have really been very well brought up.This one is full of life ... if you have nothing against this youth coming on a passing visit, will you telegraph to me."However, the request was denied on political grounds, as Prince John was married to Helen of Serbia, and Konstantin never did find the marriage he longed for.In March 1918 he was exiled to the Urals by the Bolsheviks and murdered in a mineshaft near Alapayevsk, along with his brothers Prince John Constantinovich and Prince Igor Konstantinovich, his cousin Prince Vladimir Pavlovich Paley and other relatives and friends.His body was eventually buried in the Russian Orthodox Church cemetery in Beijing, which was destroyed in 1986 to build a park.

Answer: 24 March 1927