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 hand's 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 .