Introduction to the Garden Hall: The murals in the Garden Hall are the most attractive themes, and most of them revolve around one figure, Frederick the Great, the Holy Roman Emperor of the 12th century. The themes of the frescoes include the meeting between Emperor Barbarossa and the Bishop of Würzburg, and the wedding of Emperor Barbarossa. This rooftop mural is the largest in the world and was painted by Venetian muralist Tiepolo.