What sovereign duke of the Duchy of Saxe-Coburg and Gotha, composed the opera Diana von Solange in 1858?
Ernest II, Duke of Saxe-Coburg and Gotha Ernest II (German: "Ernst August Karl Johann Leopold Alexander Eduard"; 21 June 1818 – 22 August 1893) was the sovereign duke of the Duchy of Saxe-Coburg and Gotha, reigning from 1844 to his death. Ernest was born in Coburg as the eldest child of Ernest I, Duke of Saxe-Coburg-Saalfeld, and his duchess, Princess Louise of Saxe-Gotha-Altenburg. Fourteen months later, his younger brother Prince Albert was born, who became consort of Queen Victoria of the United Kingdom. Ernest's father became Duke of Saxe-Coburg and Gotha in 1826 through an exchange of territories.
Landgravine Louise of Hesse-Darmstadt (1757–1830) Landgravine Louise Auguste of Hesse-Darmstadt (30 January 1757 – 14 February 1830) was a German princess. She was the daughter of Louis IX, Landgrave of Hesse-Darmstadt. On 3 October 1775 she married duke (later grand-duke) Charles Augustus of Saxe-Weimar-Eisenach and as such a member of the court sphere of Weimar Classicism. She was held to be serious and introverted but also compassionate and sympathetic, in the aftermath of the Battle of Jena which guaranteed her part in the later "myth of Weimar" ("Weimarmythos").