The Treaty of Paris, signed on 18 April 1951 between Belgium, France, West Germany, Italy, Luxembourg, and The Netherlands established the European Coal and Steel Community (ECSC), which subsequently became part of the European Union. The treaty expired on 18 April 2001, exactly fifty years after it came into effect.
The treaty was seen as foundational in bringing together Europe in peace after the Second World War. Some of the main enemies during the war were now sharing production of coal and steel, the key-resources which previously had been central to the war effort.