Duchess Therese Petrovna of Oldenburg
Duchess Therese Wilhelmine Olga Friederike of Oldenburg (30 March 1852 – 19 April 1883) was the youngest daughter of Duke Peter Georgievich of Oldenburg and his wife Princess Therese of Nassau-Weilburg.
Christian III, Count of Oldenburg
Count Christian III of Oldenburg( first attested in 1269 in Oldenburg, – 1285 in Oldenburg) was a ruling Count of Oldenburg.
His parents were John I of Oldenburg and Richeza( or" Rixa") of Hoya- Stumpenhausen.
Anthony I, Count of Oldenburg
Anthony I, Count of Oldenburg and Delmenhorst( 1505 – 22 January 1573, Oldenburg) was a member of the House of Oldenburg and was the Imperial Count of the Counties of Oldenburg and Delmenhorst within the Holy Roman Empire of German Nation.
His parents were John V, Count of Oldenburg( 1460- 1525) and Anna of Anhalt- Zerbst.
Princess Therese of Nassau-Weilburg
Princess Therese Wilhelmine Friederike Isabelle Charlotte of Nassau-Weilburg, (
Terezya Vasilyevna Nassauskaya; 17 April 1815 in Weilburg, Duchy of Nassau – 8 December 1871 in Prague, Kingdom of Bohemia, Austria–Hungary) was a member of the House of Nassau-Weilburg and a Princess of Nassau-Weilburg by birth.
Through her marriage to Duke Peter of Oldenburg, Therese was also a Duchess of Oldenburg.
John V, Count of Oldenburg
John V, Count of Oldenburg and Delmenhorst (also counted as John XIV, including also non-ruling namesake siblings; 1460, Oldenburg – 10 February 1526, Oldenburg) was a member of the House of Oldenburg.
He was the ruling Count of Oldenburg from 1500 to 1526.
His parents were Gerhard VI, Count of Oldenburg and Adelheid of Tecklenburg.
Grand Duchess Natalia Petrovna of Russia (1718–1725)
Grand Duchess Natalia Petrovna of Russia was the youngest daughter of Peter the Great and his second wife Catherine I.
John VII, Count of Oldenburg
Count John VII of Oldenburg and Delmenhorst( nicknamed" the Dike Builder"; 9 September 1540 in Oldenburg – 12 November 1603 in Oldenburg) was a member of the House of Oldenburg and was the ruling Count of County of Oldenburg from 1573 until his death.
His parents were Count Anthony I of Oldenburg and Sophie of Saxe- Lauenburg.
Conrad I, Count of Oldenburg
Conrad I of Oldenburg (died 1347) was the Count of Oldenburg from 1344 to 1347.
He succeeded his brother, John III of Oldenburg.
He was the son of John II of Oldenburg and Hedwig of Diepholz.
Conrad married Ingeborg, the daughter of Count Gerhard IV of Holstein-Plön.
They had four children:
Conrad I of Oldenburg is also a male-line ancestor of Queen Margrethe II of Denmark, King Harald V of Norway, and of Philip, Duke of Edinburgh, and thus of Charles, Prince of Wales, and Prince William, Duke of Cambridge.
Christian II, Count of Oldenburg
Christian II, Count of Oldenburg( died 1233) was a German nobleman.
He was the ruling Count of Oldenburg from 1209 until his death.
Christian, Duke of Oldenburg
Christian, Duke of Oldenburg( born 1 February 1955) is the head of the Grand Ducal Family of Oldenburg.

Question: Where did Duchess Therese Petrovna Of Oldenburg's mother die?