Art by Simon Quaglio (1795-1878)

Quaglio came from a working dynasty of stage and architectural designers based in Munich, part of a family that had been in the trade for generations; his father Giuseppe was a scene painter and his brother Angelo an architect and painter. Simon spent his career designing sets for well over a hundred theatrical productions, and he's credited as one of the first designers to move German theater away from flat painted backdrops toward genuinely three-dimensional, built scenery, a shift that changed how depth and space worked on stage.

Outside the theater, he contributed landscape and architectural illustrations to Sulpiz Boisserée's influential publication documenting Cologne Cathedral, work that fed into the 19th-century push to finally complete the cathedral's unfinished towers. He's a name most people encounter today only through theater history rather than a museum wall, but the shift from painted flats to built sets he helped drive is still the basic assumption behind how stage design works now.