The national side of the coin features the effigy of the Belgian King Philip I and that of Grand Duke Henri of Luxembourg. In addition, both countries are depicted, with the mention of the Economic Union, and the years 1921 and 2021. As the Royal Dutch Mint will strike the coins, the mintmark of Utrecht, a mercury staff is located on the bottom together with the Belgian mint director mintmark, the coat of arms of the municipality Herzele. It also contains the initials LL, referring to the designer of the coin, Mr. Luc Luycx. The coin’s outer ring bears the 12 stars of the European flag. (Source: ecb.europa.eu)