Erfurt (ĕr´fŏŏrt), city (1994 pop. 200,800), capital of Thuringia, central Germany, on the Gera River. It is an industrial and horticultural center and a rail junction. Industries include metalworking and the manufacture of electrical apparatus, shoes, and clothing. The city is also a major exporter of processed foods and seeds. Erfurt is one of the oldest cities of Germany. It was mentioned by St. Boniface in the 8th cent., and Charlemagne later made it a center for trade with the Slavs. Martin Luther studied (1501–5) at its university (opened 1392, closed 1816), and he took his vows as an Augustinian friar at its monastery. Erfurt was a free imperial city and a member of the Hanseatic League. It passed (1664) to the electors of Mainz and (1802) to Prussia. In 1808, Napoleon I and Czar Alexander I met there at the Congress of Erfurt, and the Franco-Russian alliance concluded at Tilsit in 1807 was renewed. At a congress held at Erfurt in 1891 the German Social Democratic party adopted the Erfurt Program (see Socialist parties), which closely followed Marxist theories. Noteworthy buildings of the city include the cathedral (12th–15th cent.) and the 13th-century Church of St. Severus.