Founded in 1846 in Nuremberg, most likely by Georg Wilhelm Sussner. The company mainly produced colored pencils using the product name Creta Polycolor, which were awarded a medal at the London World's Fair in 1862. Many artists praised the "Creta Polycolor pencils" including the royal prussian court painter Eduard Hildebrandt, Ernst Rietschel, and Julius Schnorr von Carolsfeld. Acclaim was also found abroad in Sweden, Belgium, and France from artists such as Godefried Guffens, Joseph van Lerius, Carl Gustaf Qvarnström, Vincent Vidal, Johan Christoffer Boklund, and many others.
In 1886 the company was acquired by M. Nopitsch, which used a bell in their logo/marketing. So if you find a Creta Polycolor pencil imprinted with a bell symbol, this means it was produced after the takeover by Nopitsch. If no bell is shown, then it was produced by G. W. Sussner prior to 1886.
Hat tip to Bertram Nopitsch, great-grandson of Heinrich Nopitsch, for this fascinating history.