Jena (yāˈnä) [key], city (1994 pop. 100,090), Thuringia, E central Germany, on the Saale River. Manufactures of this industrial center include pharmaceuticals, glass, optical and precision instruments, and lasers. The Zeiss works, among the best-known camera and optical equipment manufacturers in the world, implemented massive layoffs in the 1990s due to economic hardship following German reunification. Jena was known in the 9th cent. and was chartered in the 13th cent. The city passed to the house of Wettin in the 14th cent. and in 1485 passed to its Ernestine line. In 1806, Napoleon I decisively defeated the Prussians at Jena. The Univ. of Jena was founded in 1557–58 and reached its height in the late 18th and early 19th cent. At that time the dramatist Friedrich von Schiller, the philosophers Hegel, Fichte, and Schelling, and the poet August Wilhelm von Schlegel taught there. Schiller wrote the Wallenstein trilogy and Goethe wrote Hermann und Dorothea at Jena; Karl Marx was granted a doctorate in 1841. In 1934 the university's name was changed to Friedrich Schiller Univ. of Jena. Noteworthy structures in the city include the Church of St. Michael (13th cent.), a 15th-century city hall, and parts of the city's medieval fortifications.