The Cockerill-Sambre group was formed in 1981 by the merger of two Belgian steel groups – SA Cockerill-Ougrée based at Seraing in the province of Liège, and Hainaut-Sambre based at Charleroi in the province of Hainaut – both being the result of post-World War II consolidations of the Belgian steel industry.

The company inherited a steel industry with significant debts and production overcapacity based on blast furnace production rather than electric furnace recycling, with numerous factory sites in constrained city locations, and adversely affected by competition in the export market from new steel-producing countries (such as South Korea and Brasil).

The strike was both a way of seeking higher wages, and passively resisting the German occupation of Belgium during World War II.

[3] In 1961 Tolmatil became part of Cockerill-Ougrée,[4][note 2] in 1962 it participated in the founding of Sidmar contributing 1bn Belgian francs of the companies 4.5bn capital.

[6][7][8] In 1970 the company merged with the Liège-based Société Métallurgique d'Espérance Longdoz, forming Cockerill-Ougrée-Providence et Espérance Longdoz;[9] the new group was the fifth largest steelmaker in the EEC, with a steel production capacity of 7million tonnes; the new group contained all the steel producing companies in the Liège basin.