German librettist, translator and lepidopterist (August 29, 1776, Leipzig, Germany – June 4, 1842, Vienna, Austria).
He wrote librettos for Paul Wranitzky, Adalbert Gyrowetz and C. Weigl among others, and translated French operas into German. In 1814 he revised the libretto of Fidelio at Ludwig van Beethoven's request.