Longwy has historically been an industrial center of the Lorraineiron mining district. The town is known for its artistic glazed pottery.
Longwy initially belonged to Lotharingia. After the division of that kingdom, the town became part of Upper Lorraine and ultimately the Duchy of Bar. Longwy was ceded to the Duke Wenceslaus I of Luxembourg in 1368, but was returned to Bar in 1378. The Duchy of Bar was then annexed into the Duchy of Lorraine in 1480.