Benelux is the region of Europe comprised of Belgium, the Netherlands and Luxembourg. The name is formed from the beginning of each country's name, and was created for the Benelux Economic Union, but is now used in a more generic way.
The Benelux Economic Union was established in 1944 to promote the free movement of workers, capital, services, and goods in the region. Its founding contributed to the founding of the European Union (EU), though the immediate precusors to the EU were founded earlier (the ECSC in 1951 and the EEC in 1957). The three countries were also founding members of these organisations, together with West Germany, France and Italy.