The discovery of iron ore in Luxembourg in the 1850s and the introduction of metallurgy in 1876 led to the development of an important national steel industry, especially in the south of the country, and provided Luxembourg with sustained economic growth during the second half of the 19th century. This economic growth was greatly boosted during the two decades preceding World War I when large integrated steelworks, able to convert cast iron into steel and rolled steel, were constructed. Steel production surged from 145 313 tonnes in 1900 to 1 115 004 tonnes in 1913, and steel-making accounted for around 60% of total industrial employment in Luxembourg before World War I. The close economic relationship between Luxembourg and its neighbours, especially Germany, enabled investors to develop cross-border projects. As early as 1856, Luxembourg industrialists and members of parliament founded the "Saarbrücker Eisenhüttengesellschaft - Société en participation des Forges de Sarrebruck" ("Saarbrücken Ironworks shareholding company"). Similarly, German industrialists invested funds in the development of Luxembourg steel companies.