Duke Georg August of Mecklenburg-Strelitz
Georg August( 11 January 1824 – 20 June 1876) was a member of the House of Mecklenburg- Strelitz and titular duke of Mecklenburg- Strelitz.
Duchess Helene of Mecklenburg-Strelitz
Duchess Helene of Mecklenburg-Strelitz (16 January 1857 – 28 August 1936) was a daughter of Duke Georg August of Mecklenburg-Strelitz and his wife, Grand Duchess Catherine Mikhailovna of Russia.
She was the second wife of Prince Albert of Saxe-Altenburg.
Duke Carl Gregor of Mecklenburg
Carl Gregor Duke of Mecklenburg( 14 March 1933 – 23 July 2018) was a member of the House of Mecklenburg- Strelitz and a music and art historian.
Princess Elisabeth of Anhalt
Princess Elisabeth of Anhalt (7 September 1857 – 20 July 1933) was the Grand Duchess of Mecklenburg-Strelitz from 1904 to 1914 as the spouse of Adolf Friedrich V, Grand Duke of Mecklenburg-Strelitz.
Duchess Charlotte Georgine of Mecklenburg-Strelitz
Duchess Charlotte Georgine Luise Friederike of Mecklenburg- Strelitz( 17 November 1769 – 14 May 1818) was a member of the House of Mecklenburg- Strelitz and a Duchess of Mecklenburg- Strelitz by birth and a Duchess of Saxe- Hildburghausen through her marriage to Frederick, Duke of Saxe- Hildburghausen( later Duke of Saxe- Altenburg).
Georg Alexander, Duke of Mecklenburg
Georg Alexander, Duke of Mecklenburg( 27 August 1921 – 26 January 1996) was the head of the House of Mecklenburg- Strelitz from 1963 until his death.
Karl Alexander, 5th Prince of Thurn and Taxis
Karl Alexander, 5th Prince of Thurn and Taxis, full German name: "Karl Alexander Fürst von Thurn und Taxis" (22 February 1770 – 15 July 1827) was the fifth Prince of Thurn and Taxis, head of the Thurn-und-Taxis-Post, and Head of the Princely House of Thurn and Taxis from 13 November 1805 until his death on 15 July 1827.
With the death of his father on 13 November 1805, he became nominal "Generalpostmeister" of the Imperial Reichspost until the resignation of Francis II, Holy Roman Emperor.
Princess Augusta of Cambridge
Princess Augusta of Cambridge( 19 July 1822 – 5 December 1916) was a member of the British Royal Family, a granddaughter of George III.
She married into the Grand Ducal House of Mecklenburg- Strelitz and became the Grand Duchess of Mecklenburg- Strelitz.
Duchess Gustave Caroline of Mecklenburg-Strelitz
Duchess Gustave Caroline of Mecklenburg- Strelitz( 12 July 1694 – 13 April 1748) was a daughter of Adolphus Frederick II, Duke of Mecklenburg and Princess Maria of Mecklenburg.
Duchess Therese of Mecklenburg-Strelitz
Duchess Therese Mathilde Amalie of Mecklenburg-Strelitz (5 April 1773 – 12 February 1839) was a member of the House of Mecklenburg-Strelitz and a Duchess of Mecklenburg.
Through her marriage to Karl Alexander, 5th Prince of Thurn and Taxis, Therese was also a member of the House of Thurn and Taxis.

Question: What is the date of death of Duchess Therese Of Mecklenburg-Strelitz's husband?
Answer: 15 July 1827