Prince Moritz of Saxe-Altenburg
Prince Moritz Franz Friedrich Constantin Alexander Heinrich August Carl Albrecht of Saxe- Altenburg( 24 October 1829 in Eisenberg – 13 May 1907 in Arco, Italy), was a member of the ducal house of Saxe- Altenburg.
He was the father of Ernst II, Duke of Saxe- Altenburg.
Georg Moritz, Hereditary Prince of Saxe-Altenburg
George Moritz, Hereditary Prince of Saxe- Altenburg(" William George Moritz Ernest Albert Frederick Charles Constantine Edward Maximilian"; 13 May 1900 – 13 February 1991), was the last head of the ducal house of Saxe- Altenburg and nominal Duke of Saxe- Altenburg.
He devoted much of his life to promote anthroposophy.
Princess Marie Anne of Saxe-Altenburg
Princess Marie Anne of Saxe- Altenburg( 14 March 1864 – 3 May 1918) was the consort of Georg, Prince of Schaumburg- Lippe.
As the eldest daughter of Prince Moritz of Saxe- Altenburg and his wife Princess Augusta of Saxe- Meiningen, and a sister of Ernest II, Duke of Saxe- Altenburg, Marie Anne was a member of the Ducal House of Saxe- Altenburg.
Joseph, Duke of Saxe-Altenburg
Joseph Georg Friedrich Ernst Karl, Duke of Saxe- Altenburg( 27 August 1789 in Hildburghausen – 25 November 1868 in Altenburg), was a duke of Saxe- Altenburg.
He was the second but first surviving son of Frederick, Duke of Saxe- Hildburghausen( of Saxe- Altenburg from 1826) and Duchess Charlotte Georgine of Mecklenburg- Strelitz.
Joseph succeeded his father as Duke of Saxe- Altenburg after his death in 1834.
In 1814, he and his brother George fought with the allies against France in the Napoleonic Wars.
Later he was a General Major in Saxon services.
He implemented several buildings in Altenburg, but his government was considered conservative and resistant to reform; for this, he was forced to abdicate during the civil revolution of 1848.
In Kirchheim unter Teck on 24 April 1817 Joseph married Amelia of Württemberg, a daughter of Duke Louis of Württemberg.
They had six daughters:
Ernst I, Duke of Saxe-Altenburg
Ernst I, Duke of Saxe-Altenburg (German: Ernst I. Friedrich Paul Georg Nikolaus von Sachsen-Altenburg) (16 September 1826 in Hildburghausen – 7 February 1908 in Altenburg), was a duke of Saxe-Altenburg.
He was the first son of Georg, Duke of Saxe-Altenburg and Marie Luise of Mecklenburg-Schwerin.
In 1853 he succeeded his father as Duke of Saxe-Altenburg.
He was of a retiring disposition and he took little active part in running the country.
After a reign that lasted fifty five years, he died without a living direct male heir; because of this, he was succeeded by his nephew, Ernst.
Princess Charlotte of Saxe-Altenburg
Princess Charlotte Agnes of Saxe- Altenburg( 4 March 189916 February 1989) was the eldest child of Ernst II, the last reigning duke of Saxe- Altenburg.
Princess Elisabeth Sophie of Saxe-Altenburg
Elisabeth Sophie of Saxe- Altenburg( 10 October 1619 – 20 December 1680), was a princess of Saxe- Altenburg and, by marriage, duchess of Saxe- Gotha.
She was born in Halle, the only daughter of Johann Philipp, Duke of Saxe- Altenburg, and his wife, Elisabeth of Brunswick- Wolfenbüttel.
Princess Agnes of Anhalt-Dessau
Princess Agnes of Anhalt- Dessau( Frederica Amalia Agnes; 24 June 1824 – 23 October 1897) was the eldest daughter of Leopold IV, Duke of Anhalt by his wife Princess Frederica of Prussia.
She was a member of the House of Ascania, and by her marriage to Ernst I, Duke of Saxe- Altenburg, Duchess consort of Saxe- Altenburg.
Georg, Duke of Saxe-Altenburg
Georg Karl Frederick (24 July 1796 in Hildburghausen – 3 August 1853 in Hummelshain) was a duke of Saxe-Altenburg.
Princess Augusta of Saxe-Meiningen
Princess Augusta Louise Adelaide Caroline Ida of Saxe-Meiningen (6 August 1843 – 11 November 1919) was the daughter of Bernhard II, Duke of Saxe-Meiningen and his wife Princess Marie Frederica of Hesse-Kassel.
She was the mother of Ernst II, Duke of Saxe-Altenburg.

Question: Where did Ernst I, Duke Of Saxe-Altenburg's father die?