500 Francs / 100 Belgas

The Belga was a trade-weighted unit introduced by Belgium in 1926, pegged at five francs, and used primarily in foreign exchange transactions rather than everyday commerce. Printing denominations in both Francs and Belgas was a practical concession to that dual-track monetary arrangement, not an aesthetic choice. The Belga designation was quietly abandoned after 1944 and never revived.

Albert Doms worked extensively for the National Bank's in-house printing works during this period, and his engraving on this series is among the finer intaglio work produced domestically in interwar Belgium — worth noting precisely because the Bank chose not to contract abroad, as many smaller issuers did.