5 Francs – Belgium

In 1865, Belgium's currency situation was defined by its pivotal role in the formation of the Latin Monetary Union (LMU). Following its independence in 1830, Belgium had initially adopted a monetary system closely aligned with that of France, based on a bimetallic standard of gold and silver. However, the mid-19th century saw significant instability in the relative values of these two metals, causing disruptive arbitrage and threatening the stability of national coinages across Europe. Belgium, alongside France, Italy, and Switzerland, sought a multilateral solution to this problem.

Consequently, on December 23, 1865, the four nations signed the treaty that established the Latin Monetary Union. This agreement created a standardized, bimetallic currency bloc where each member's coins—the Belgian franc, French franc, Italian lira, and Swiss franc—were defined by identical weights of gold and silver (4.5 grams of fine silver or 0.290322 grams of fine gold for a franc) and were granted legal tender status across all member states. For Belgium, this formalized and strengthened its existing monetary ties with France, ensuring the free circulation of its currency with its major economic partners and stabilizing exchange rates.

The immediate background in 1865 was thus one of proactive international cooperation to overcome the flaws of bimetallism. The LMU aimed to facilitate trade and travel by eliminating exchange risk within Western Europe. While successful in the short term, the Union would later face strains from members over-issuing silver token coins and the global shift toward a gold standard. Nevertheless, in 1865, Belgium's currency was at the forefront of a pioneering, albeit ultimately unsustainable, experiment in European monetary integration.