Giessen, a town of Germany, capital of the province of Upper Hesse, in the grand-duchy of Hesse-Darmstadt, is situated in a beautiful and fruitful valley at the confluence of the Wieseck with the Lahn, 41 m. N.N.W. of Frankfort-on-Main on the railway to Cassel; and at the junction of important lines to Cologne and Coblenz. Pop. (1885) 18,836; (1905) 29,149. In the old part of the town the streets are narrow and irregular. Besides the university, the principal buildings are the Stadtkirche, the provincial government offices, comprising a portion of the old castle dating from the 12th century, the arsenal (now barracks) and the town-hall (containing an historical collection). The university, founded in 1607 by Louis V, landgrave of Hesse, has a large and valuable library, a botanic garden, an observatory, medical schools, a museum of natural history, a chemical laboratory which was directed by Justus von Liebig, professor here from 1824 to 1852, and an agricultural college. The industries include the manufacture of woollen and cotton cloth of various kinds, machines, leather, candles, tobacco and beer.
Giessen, the name of which is probably derived from the streams which pour (giessen) their waters here into the Lahn, was formed in the 12th century out of the villages Selters, Aster and Kroppach, for whose protection Count William of Gleiberg built the castle of Giessen. Through marriage the town came, in 1203, into the possession of the count palatine, Rudolph of Tübingen, who sold it in 1265 to the landgrave Henry of Hesse. It was surrounded with fortifications in 1530, which were demolished in 1547, but rebuilt in 1560. In 1805 they were finally pulled down, and their site converted into promenades.
See O. Buchner, Führer für Giessen und das Lahntal (1891); and Aus Glessens Vergangenheit (1885).