100 Years of the Economic Union with Luxembourg

Portraits of King Philippe alongside Grand Duke Henri of Luxembourg. To the right, outlines of Belgium and Luxembourg with the inscription 'ECONOMIC UNION' and the country codes 'BE' and 'LUX'. Below the portraits, the years '1921' and '2021', together with the mint master's mark and the mint mark of the Royal Dutch Mint. The initials 'LL' of designer Luc Luycx appear at the lower right.

Belgium and Luxembourg have shared one of Europe's oldest and closest economic integrations since 1921. The Belgium-Luxembourg Economic Union (BLEU) created a common currency and customs area that brought considerable benefits to both countries despite their difference in size: Luxembourg gained access to the Belgian industrial market and the port of Antwerp, while Belgium benefited from the Grand Duchy's strategic location and growing financial sector. The 1921 treaty was a direct response to the economic upheavals of the First World War and is regarded as an early precursor of later European economic integration.

Over the course of the 20th century, the union continued to develop and remained institutionally relevant in both countries even after the introduction of the euro in 2002. Luxembourg today is among the wealthiest countries in the world, with one of the highest per-capita gross domestic products globally — a development that would hardly have unfolded this way without its early economic ties to Belgium. Both countries are founding members of the European Communities and have played a major role in shaping European integration. In 2021, Belgium marked the centenary of this bi-national economic partnership with a joint commemorative issue together with Luxembourg.