In 1938, the Grand Duchy of Luxembourg operated within the framework of the
Belgium-Luxembourg Economic Union (BLEU), established in 1922. This union created a fixed exchange rate parity, where the Luxembourgish franc was legally equivalent to and freely interchangeable with the Belgian franc. Consequently, Luxembourg did not have a fully independent monetary policy; its currency circulation was largely managed in tandem with Belgium, with Belgian banknotes also being legal tender within the Grand Duchy. This system provided economic stability and facilitated seamless cross-border trade with its most important economic partner.
The period leading up to 1938 was one of global economic uncertainty following the Great Depression. Luxembourg's economy, heavily reliant on steel exports, was vulnerable to international market fluctuations. While the BLEU arrangement offered stability, it also meant Luxembourg's currency was indirectly affected by Belgium's monetary decisions and its own economic challenges. Domestically, Luxembourg issued its own franc coins and, notably, a series of franc banknotes through the
Luxembourg Monetary Institute (Institut Monétaire Luxembourgeois), founded in 1935 to oversee the issuance of distinct Luxembourgish currency within the union.
Politically and economically, 1938 was a tense and pivotal year on the eve of World War II. The currency system, while robust in peacetime economic union, faced an existential threat from looming German expansionism. The stability of the Luxembourg franc was therefore underpinned not only by its link to Belgium but also by the fragile geopolitical situation in Europe. Within a few years, this arrangement would be violently disrupted by the German invasion in May 1940, which led to the immediate abolition of the Luxembourg franc and its forced replacement with the German Reichsmark.