Gustav Grohe, German, 1829 to 1909, a rare and highly collectible 19th century German high relief cast spelter plaque depicting Lohengrin from the famous opera of Wagner. Lohengrin is the hero of German tales about King Arthur. The son of Parzival, he is a knight of the Holy Grail, sent in a boat pulled by swans to rescue the maiden, who must never ask about his origins. His story is a version of the legend of the Knight of the Swan. The plaque is of a round shape, housed in a beautifully ornate frame with lion masks to the corners and having a tapestry depicting a courting couple which is placed behind the plaque. Marked: Gust. Grohe, titled Lohengrin. Antique Metal Work Art And Wall Decor Collectibles.