Princess Marie of Denmark
Princess Marie of Denmark, Countess of Monpezat,(" née" Marie Agathe Odile Cavallier, born 6 February 1976) is the second wife of Prince Joachim of Denmark.
Prince Karl Franz of Prussia
Prince Karl Franz of Prussia( 15 December 1916 – 23 January 1975) was the only child of Prince Joachim of Prussia and his wife Princess Marie- Auguste of Anhalt.
He was also the grandson of Wilhelm II, German Emperor, himself a grandson of Queen Victoria, which made Prince Karl a great- great- grandson of the British queen.
Princess Alexandrine of Prussia (1842–1906)
Princess Frederica Wilhelmina Louise Elisabeth "Alexandrine" of Prussia (1 February 1842 – 26 March 1906) was a member of the House of Hohenzollern as the daughter of Prince Albert of Prussia and his wife Princess Marianne of the Netherlands.
Prince Joachim Albert of Prussia
Prince Joachim of Prussia (27 September 1876 – 24 October 1939) was a member of the House of Hohenzollern.
He was the second eldest son of Prince Albert of Prussia and his wife Princess Marie of Saxe-Altenburg.
He is notable for composing music, in particular military waltzes.
Princess Marianne of Prussia
Princess Marianne of Prussia( 23 August 19131 March 1983) was a member of the House of Hohenzollern, daughter of Prince Friedrich Wilhelm of Prussia.
Princess Marie of Prussia (1855–1888)
Princess Marie of Prussia(" Marie Elisabeth Louise Frederika"; 14 September 1855, Marmorpalais, Potsdam – 20 June 1888, Dresden), was a princess of the House of Hohenzollern.
She was the daughter of Prince Frederick Charles of Prussia and later became second wife of Prince Henry of the Netherlands then the first wife of Prince Albert of Saxe- Altenburg.
She was also the great- niece of Wilhelm I, German Emperor.
Princess Marie of Saxe-Altenburg (1854–1898)
Princess Marie of Saxe-Altenburg (Marie Friederike Leopoldine Georgine Auguste Alexandra Elisabeth Therese Josephine Helene Sophie; 2 August 1854 – 8 October 1898) was the wife of Prince Albert of Prussia, Regent for the duchy of Brunswick.
Prince Friedrich Sigismund of Prussia (1891–1927)
Prince Joachim Viktor Wilhelm Leopold Friedrich Sigismund of Prussia( 17 December 1891 – 6 July 1927) was a German World
War I fighter pilot and member of the House of Hohenzollern.
He was the son of Prince Friedrich Leopold of Prussia and Princess Louise Sophie of Schleswig- Holstein- Sonderburg- Augustenburg, married in 1916.
Princess Charlotte of Prussia (1831–1855)
Princess Charlotte of Prussia( 21 June 1831 – 30 March 1855), was by birth a Princess of Prussia and member of the House of Hohenzollern and by marriage Hereditary Princess of Saxe- Meiningen.
She was the eldest child and daughter of Prince Albert of Prussia( younger son of Frederick William III of Prussia and Louise of Mecklenburg- Strelitz) and his first wife Princess Marianne of the Netherlands( daughter of William I of the Netherlands and Wilhelmine of Prussia).
Alexandra, Countess of Frederiksborg
Alexandra, Countess of Frederiksborg,(" née" Alexandra Christina Manley; born 30 June 1964) is the first wife of Prince Joachim of Denmark, the younger son of Margrethe II of Denmark.
She was born in Hong Kong and is of mixed Chinese- European ancestry.
She was introduced to Prince Joachim in 1994.
They married in 1995 and had two sons together, until the marriage was dissolved in 2005.

Question: When did Prince Joachim Albert Of Prussia's mother die?