It follows a continuous stretch of valleys of the rivers Haine, Sambre, Meuse and Vesdre, and has an area of roughly 1000 km2.
The sillon industriel was the first fully industrialized area in continental Europe,[2] experiencing its first industrialisation wave from 1800 to 1820.
This continued until after World War II, when the importance of Belgian steel, coal and industry began to diminish.
The region's economy shifted towards extraction of non-metallic raw materials such as glass and soda, which lasted until the 1970s.
[citation needed] The region was at the heart of the general strike of winter 1960-1961, which helped Wallonia to gain autonomy.