CHARLEROI (Carolus Rex), a town in the province of Hainaut, Belgium. Pop. (1904) 26,528. It was founded in 1666 on the site of a village called Charnoy by the Spanish governor Roderigo and named after his sovereign Charles II. of Spain. Charleroi is the centre of the iron industry of Belgium. It is connected by a canal with Brussels, and from its position on the Sambre enjoys facilities of communication by water with France as well as Belgium. It was ceded soon after its foundation to France by the treaty of Aix-la-Chapelle, and Vauban fortified it. During the French occupation the town was considerably extended, and the fortifications were made so strong that Charleroi twice successfully resisted the strenuous attacks of William of Orange. In 1794 Charleroi again fell into the hands of the French, and on this occasion instead of fortifying they dismantled it. In 1816 Charleroi was refortified under Wellington’s direction, and it was finally dismantled in 1859. Some portions of the old ramparts are left near the railway station. There is an archaeological museum with a miscellaneous collection of Roman and Frank antiquities.