Saalfeld (zälˈfĕlt) [key], city (1994 pop. 31,981), Thuringia, E central Germany, on the Thüringer Saale River. Manufactures include machinery, chocolate, and dyes. Iron is mined and slate is quarried nearby. Saalfeld was founded c.1200 and in the 16th cent. was a silver-mining center. It was the capital of the duchy of Saxe-Saalfeld from 1680 to 1735. In 1806 the French defeated the Prussians there during the Napoleonic Wars. The duke of Saxe-Coburg exchanged (1826) Saalfeld for Gotha with the duke of Saxe-Meiningen. Noteworthy buildings of the city include a 14th-century church, a 16th-century city hall, a 13th-century Franciscan monastery (now a museum), a 13th-century castle, and an 18th-century palace.