Subject of the commemorative coin:
 100th anniversary of the founding of the Belgian-Luxembourg Economic Union (BLEU)

 Description of the design:
 The national side of the coin features the effigies of King Philippe I of Belgium and Grand Duke Henri of Luxembourg. In addition, both countries are depicted, with the words “ECONOMIC UNION”, and the years 1921 and 2021. Since the Royal Dutch Mint will strike the coin, the Utrecht mint mark, a mercury staff, is at the bottom, together with the Belgian mint master mark, the coat of arms of the municipality of Herzele. The coin also features the initials LL, a reference to the designer of the coin, Mr. Luc Luycx. The outer ring of the coin features the twelve stars of the European flag.