Dr. Carl Wilhelm Hahn (lat. Carolus Guilielmus Hahn) (* 16 December 1786 – † 7 November 1835) was a German zoologist and author of the first German monograph on spiders. C. W. Hahn was an all-round natural scientist – not at all unusual for his time. Surprisingly he seems to have been almost forgotten. Even the few biographical dates, which have been published in secondary literature are not always correct as clarified by P. Sacher in his "attempt at a Biography":


Carl Wilhelm Christian Hahn was born in Weingartsgreuth, Upper Franconia as the first son of Johann Michael Hahn (1734–1824), who was court and palace gardener on the estate of Baron von Seckendorff, later palace gardener for Count Friedrich von Pückler. C. W. Hahn obeyed the general call to arms as early as 1813. He served as a quarter master and in 1816 received his honourable discharge. Afterwards he lived with his parents in Fürth and, according to Hahn, made up his mind to devote his life to his predilection for natural history, an interest he had had since early childhood and which intensified during his studies in Erlangen. He commenced work on his first ornithological work "Birds from Asia, Africa, America and New Holland". When his "often promised and well earned position" failed to materialize, Hahn undertook what was for that time, in his field, a very unusual step and went freelance. From then on he called himself a natural historian and occasionally also a scholar. On 24 February 1820, having in the meantime qualified as a Dr. Phil. at the University of Erlangen, he married Victoria Francisca Kaltdorff, née Schaefer. His wife, the widow of a doctor of medicine, was about five years older than he, and had three children by her previous marriage. She was at this time without means, but was expecting quite large inheritance from her maternal uncle before long. Their own child Anna Friedericke was born at the end of 1820 or 1821.