A scholarly book about the «Theatre Duke» Ernst II of Saxe-Coburg and Gotha, who composed 5 grand operas which were performed all over Germany and even in the US, has come out: "Macht und Musik. Herzog Ernst II. von Sachsen-Coburg und Gotha und das Musiktheater im 19. Jahrhundert", written by Angelika Tasler, published by Böhlau – http://www.boehlau-verlag.com
Interesting. He was the elder brother of Queen Victoria's Prince Albert. I think that Liszt paraphrased music from at least one of the operas.
He did indeed Mark - there is a rather lovely transcription of the song Song "Die Gräberinsel", a transcription of part of the opera "Tony" entitled "Halloh! Jagdchor und Steyrer" and also a march based on themes from "Diana von Salange" called "Festmarsch nach Motiven von E.H.z.S.-C.-G" which exists in 3 versions - solo piano, piano duet and orchestra.