Question: What was the title of the father of this sovereign duke of the Duchy of Saxe-Coburg and Gotha who composed the opera "Diana von Solange"?
Sentence (from "Ernest II, Duke of Saxe-Coburg and Gotha"): Ernest's father became Duke of Saxe-Coburg and Gotha in 1826 through an exchange of territories.
Relevant evidence: No