Bad Langensalza (bät läng´ənzäl´tsä), town (1994 pop. 17,350), Thuringia, S central Germany, on the Unstrut River. It is an industrial and horticultural center. Manufactures include textiles, paper, processed food, and beer. Bad Langensalza was an early seat (13th cent.) of the Teutonic Knights. The town was annexed (14th cent.) by the house of Wettin, passing to its Albertine line in 1485. Bad Langensalza was annexed by Prussia in 1815, and in 1866 the Prussians defeated the Hanoverians there in a battle during the Austro-Prussian War. The town has retained parts of its medieval walls and a 13th-century castle.