Karl Haffner ( pseudonym ), actually: Karl Schlechter was a German dramatist .
Karl Haffner visited the Collegium Fridericianum in Königsberg. The age of 16 he joined a traveling troupe and traveled through as a traveling comedian Prussia, Saxony, Silesia, Austria and Hungary. After ten years he was a playwright and dramatist at the Pest theater at Feodor Grimm, after he had previously made some dramatic experiments.
Read more about Karl Haffner on Wikipedia.