William married Olga Constantinovna Princess of Greece Romanov in 1867 in Winter Palace, St Petersburg, Russia. Olga (daughter of Konstantin Nicholaievich Romanov and Princess Alexandra Of Saxony -Altenburg) was born on 3 Sep 1851 in Pavlovsk, Altai Mountains, Russia; died on 18 Jun 1926 in Rome, Roma, Lazio, Italy; was buried in Athens, Regional unit of Athens, Attica, Greece. [Group Sheet] [Family Chart]

1. Andrew (Prince of Greece and Denmark) OLDENBURG MONTBATTEN was born on 2 Feb 1882 in Athínai, Attiki, Attiki, Greece; died on 3 Dec 1944 in Monte Carlo, Monaco.

Family/Spouse: Unknown. [Group Sheet] [Family Chart]

1. Christopher Oldenberg was born in 1867; died in 1873.
2. Constantine I, King of Greece, Oldebburg was born on 2 Aug 1868 in Athínai, Attiki, Greece; died on 11 Jan 1923 in Palermo, Sicilia, Italy.
3. George, High Commissioner of Crete, Oldenburg was born in 1869 in Corfu, Greece; died in 1957 in Chateau de Saint Cloud, Ile-de-France, France.
4. Alexandra Georgievna, Grand Duchess, Oldenburg was born on 10 Aug 1870 in Kérkyra, Ionian Islands, Greece; died on 24 Sep 1891 in Moskva, Moscow City, Russia.
5. Nicholas, Prince of Greece, Oldenburg was born on 9 Jan 1872 in Athínai, Attiki, Attiki, Greece; died on 8 Feb 1938 in Athínai, Attiki, Attiki, Greece.
6. Marie Georgiviena, Princess of Greece, George was born on 20 Feb 1876 in Athínai, Greece; died on 14 Dec 1940 in Athínai, Greece.
7. Olga Schleswig Holstein Sonderburg was born on 7 Apr 1880 in Athens, Greece; died on 2 Nov 1880 in Athens, Greece.
8. Christopher, Prince of Greece, Schleswig Holstein was born on 11 Aug 1888 in Pavlovsk, Altai Mountains, Russia; died on 21 Jan 1940 in Athens, Athens, Ohio, United States.

Christian married Louise Wilhelmina Fredricka Carolina Hesse Kassel Rumpenheim. Louise was born on 7 Sep 1817 in Cassel, Ahrweiler, Rheinland-Pfalz, Germany; died on 29 Sep 1898 in Bernstorff, Ludwigslust, Mecklenburg-Vorpommern, Germany. [Group Sheet] [Family Chart]