Grand Duke Nicholas Konstantinovich of Russia
Grand Duke Nicholas Constantinovich of Russia( 14 February 1850 – 26 January 1918) was the first- born son of Grand Duke Konstantin Nikolayevich and Grand Duchess Alexandra Iosifovna of Russia and a grandson of Nicholas I of Russia.
Ogawa Mataji
Viscount was a general in the early Imperial Japanese Army.
He was also the father- in- law of Field Marshal Gen Sugiyama.
Grand Duchess Xenia Alexandrovna of Russia
Grand Duchess
Xenia Alexandrovna of Russia( – 20 April 1960) was the elder daughter and fourth child of Tsar Alexander III of Russia and Empress Maria Feodorovna of Russia( née Princess Dagmar of Denmark) and the sister of Emperor Nicholas II.
She married a cousin, Grand Duke Alexander Mikhailovich of Russia, with whom she had seven children.
She was the mother- in- law of Felix Yusupov and a cousin of Grand Duke Dmitri Pavlovich of Russia who, together, killed Grigori Rasputin, holy healer to her nephew, the haemophiliac Tsarevich Alexei Nikolaevich of Russia.
During her brother's reign she recorded in her diary and letters increasing concern about his rule.
After the fall of the monarchy in February 1917, she fled Russia, eventually settling in the United Kingdom.
Her grandson Prince Andrew Andreevich has been a head of the Romanov Family since December 2016.
Grand Duke Kirill Vladimirovich of Russia
Grand Duke Kirill Vladimirovich of Russia, ("Kirill Vladimirovich Romanov"; – 12 October 1938) was a son of Grand Duke Vladimir Alexandrovich of Russia, a grandson of Emperor Alexander II and a first cousin of Nicholas II, Russia’s last Tsar.
Grand Duke Kirill followed a career in the Russian navy serving during twenty years in the Naval Guards.
He took part in the Russo-Japanese War, barely surviving the sinking of the battleship at Port Arthur in April 1904.
In 1905, he married his paternal first cousin, Princess Victoria Melita of Saxe-Coburg and Gotha.
They wed in defiance of Tsar Nicholas II prohibition.
In retaliation, the Tsar stripped Kirill of his offices and honors, also initially banishing the couple from Russia.
They had two daughters and settled in Paris before being allowed to visit Russia in 1909.
In 1910 they moved to Russia, where Nicholas II recognized their marriage.
During World War I, Grand Duke Kirill was appointed Commander of the Naval Depot of the Guards in 1915 and in 1916, he achieved the rank of rear Admiral in the Imperial Navy.
During the February Revolution of 1917, Kirill marched to the Tauride Palace at the head of the Naval Guards swearing allegiance to the Russian Provisional Government.
During the rule of the provisional governmental in the summer 1917, Kirill escaped to Finland where his wife gave birth to the couple's only son.
In exile they lived for some years among his wife's relatives in Germany, and from the late 1920s on an estate they bought in Saint-Briac.
With the murder of his cousins Tsar Nicholas II and Grand Duke Michael, Kirill assumed the headship of the Imperial Family of Russia and, as next in line to the throne as the Guardian of the Throne in 1924.
Kirill proclaimed himself emperor in exile in 1926.
He worked for the restoration of the monarchy from exile for the rest of his life, but his claims were contested by some factions of the monarchy movement in a division that continues until today.
He wrote a book of memoirs, "My Life in Russia's Service", published after his death.
His granddaughter, Grand Duchess Maria Vladimirovna, is the current claimant to the headship of the House of Romanov.
Prince Karl of Leiningen
Prince Karl Vladimir Ernst Heinrich of Leiningen( 2 January 1928 – 28 September 1990) was the younger son of Karl, 6th Prince of Leiningen( 1898 – 1946) and Grand Duchess Maria Kirillovna of Russia.
Maria was the daughter of Princess Victoria Melita of Edinburgh and Saxe- Coburg- Gotha and Cyril Vladimirovich, Grand Duke of Russia.
As such, Karl was a great- great- grandson of both Queen Victoria of Great Britain and Emperor Alexander II of Russia( as Victoria Melita and Cyril Vladimirovich were both grandchildren of Alexander II).
Louis II, Grand Duke of Baden
Louis II, Grand Duke of Baden( 15 August 1824 – 22 January 1858) was the son of Leopold I, Grand Duke of Baden and Sophie of Holstein- Gottorp, Princess of Sweden.
Louis succeeded his father as Grand Duke of Baden on 24 April 1852.
His brother Frederick acted as regent, because Louis suffered from mental illness.
However, in 1856, Frederick became grand duke as well.
He was also an honorary citizen of Karlsruhe.
Grand Duke Vyacheslav Konstantinovich of Russia
Grand Duke Vyacheslav Konstantinovich of Russia,( 13 July 1862 – 27 February 1879), was a Romanov grand duke and the youngest son of Grand Duke Konstantin Nikolayevich of Russia and his wife Princess Alexandra of Saxe- Altenburg.
The English form of his first name is Wenceslas.
Abdul-Vahed Niyazov
' of Russia.
Nikolaus, Hereditary Grand Duke of Oldenburg
Nikolaus, Hereditary Grand Duke of Oldenburg( 10 August 18973 April 1970) was the eldest son of Frederick Augustus II, Grand Duke of Oldenburg, who was the last ruling Grand Duke of Oldenburg.
In 1931, Nikolaus succeeded to his father's titles and assumed the role of pretender to the Grand Duchy, until his death in 1970.
Princess Victoria Melita of Saxe-Coburg and Gotha
Princess Victoria Melita of Saxe-Coburg and Gotha , later Grand Duchess Victoria Feodorovna of Russia (25 November 1876 – 2 March 1936) was the third child and second daughter of Alfred, Duke of Saxe-Coburg and Gotha, and Grand Duchess Maria Alexandrovna of Russia.
She was a granddaughter of Queen Victoria of the United Kingdom and Emperor Alexander II of Russia.
Born a British princess, Victoria spent her early life in England and lived in Malta for three years, where her father was serving in the Royal Navy.
In 1889 the family moved to Coburg, where Victoria's father became the reigning duke in 1893.
In her teens Victoria fell in love with her maternal first cousin Grand Duke Kirill Vladimirovich of Russia, but the disapprobation of marriage between first cousins of his faith, Orthodox Christianity, discouraged their romance.
Bowing to family pressure, Victoria married her paternal first cousin, Ernest Louis, Grand Duke of Hesse and by Rhine in 1894, following the wishes of their grandmother, Queen Victoria.
Their marriage was a failure.
Victoria scandalized the royal families of Europe when she divorced her husband in 1901.
The couple's only child, Princess Elisabeth of Hesse and by Rhine, died of typhoid fever in 1903.
Victoria married Grand Duke Kirill Vladimirovich in 1905.
They wed without the formal approval of Britain's King Edward VII, required by the Royal Marriages Act 1772, and in defiance of Tsar Nicholas II.
In retaliation, the Tsar stripped Kirill of his offices and honours, also initially banishing the couple from Russia.
They had two daughters and settled in Paris before being allowed to visit Russia in 1909.
In 1910 they moved to Russia, where Nicholas recognized her as Grand Duchess Victoria Feodorovna.
After the fall of the Russian monarchy in 1917, they escaped to Finland (then part of the Russian Empire) where she gave birth to her only son.
In exile they lived for some years among her relatives in Germany, and from the late 1920s on an estate they bought in Saint-Briac.
In 1926, Kirill proclaimed himself emperor in exile and Victoria supported her husband's claims.
Victoria died after suffering a stroke while visiting her daughter Maria in Amorbach.

Question: Who is Grand Duke Kirill Vladimirovich Of Russia's father-in-law?