What sovereign duke of the Duchy of Saxe-Coburg and Gotha, composed the opera Diana von Solange in 1858?
Diana von Solange:  It was premiered 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.
i don't know