Arad (ärädˈ) [key], city (1990 pop. 203,198), W Romania, in the Banat, on the Mureşul River, near the Hungarian border. It is an important railroad junction and a leading regional commercial and industrial center. Distilling, sawmilling, and the manufacture of machine tools and locomotives are the chief industries. Located on the site of an old Roman outpost, the first mention of Arad dates from the 12th cent. Long (c.1551–1685) under Turkish rule, Arad passed in 1685 to the Austrians and in 1849 to the Hungarians, who made it the headquarters of their insurrection against the Hapsburg Empire. In 1920, Arad became part of Romania. The city's educational and cultural institutions include a theological seminary, a teacher training school, a state theatre, a philharmonic orchestra, and a museum containing exhibits on the Hungarian revolution of 1848–49. The 18th-century citadel was built by Empress Maria Theresa. Arad has a sizable Hungarian population.