Bochum (bō'khoom) [key], city (1994 pop. 401,060), North Rhine–Westphalia, W Germany. Mentioned in the 9th cent. and chartered in 1321, it remained a small farming community until the development of nearby coal mines in the mid-19th cent. By the late 19th cent. it was a leading center of the Ruhr iron and steel industry; since the early 1960s its importance in coal and steel production has declined. Bochum today is an industrial and commercial center, a rail and road junction, and a growing vacation spot. Its manufactures include automobiles, metal products, chemicals, textiles, beer, and tobacco products. It is the seat of Ruhr Univ. (opened 1965) and museums of mining and geology.