Depicts the portraits in the left profile of the three first Kings of Belgium, engraver's initials below, surrounded by their names and dates.

Leopold I (1790–1865) was a German prince who became the first King of the Belgians following Belgian independence in 1830. He reigned between July 1831 and December 1865.

Born into the ruling family of the small German duchy of Saxe-Coburg-Saalfeld, Leopold took a commission in the Imperial Russian Army and fought against Napoleon after French troops overran Saxe-Coburg during the Napoleonic Wars. After Napoleon's defeat, Leopold moved to the United Kingdom where he married Princess Charlotte of Wales, the only child of the Prince Regent (the future King George IV).

After the Greek War of Independence (1821–32), Leopold was offered the position of King of Greece but turned it down, believing it to be too precarious. Instead, Leopold accepted the kingship of the newly established Kingdom of Belgium in 1831. His reign was marked by attempts by the Dutch to recapture Belgium. Leopold was considered liberal and encouraged economic modernisation, playing an important role in encouraging the creation of Belgium's first railway in 1835 and subsequent industrialisation.

Leopold II (1835–1909) reigned as the second King of the Belgians from 1865 to 1909 (the longest reign of any Belgian monarch) and became known for the founding and exploitation of the Congo Free State as a private venture. He was responsible for the death of 15 million African people.

Albert I (1875–1934) reigned as the King of the Belgians from 1909 to 1934. This was an eventful period in the history of Belgium, which included the period of World War I (1914–1918), when 90 percent of Belgium was overrun, occupied, and ruled by the German Empire. Other crucial issues included the adoption of the Treaty of Versailles, the ruling of the Belgian Congo as an overseas possession of the Kingdom of Belgium along with the League of Nations mandate of Ruanda-Urundi, the reconstruction of Belgium following the war, and the first five years of the Great Depression (1929–1934). King Albert died in a mountaineering accident in eastern Belgium in 1934, at the age of 58, and he was succeeded by his son Leopold III (r. 1934–1951).

Value (in Francs and Belgas) in the centre flanked by two stalks of laurel. Legend in French (Kingdom of Belgium) above, engraver's name below.

In 1926, the new government Jaspar works out a stabilizing program for the Belgian Franc. The introduction of the Belga currency was one of several components of the plan. One Belga was equal to 5 Belgian francs. In order to clearly distinguish this new Belgian valuta against the other currencies, especially the French Franc, all exchange operations had to be realised in Belga.

However, the Belgian Franc did not disappear, because the newly issued coins and notes always mentioned their value in both the Belga as the Belgian Franc currency. 1927 saw appearing the first notes mentioning both currencies and 3 years later ‘Belga-Franc’ coins appeared on the market.

Position A (readable from the obverse) or Position B (readable from the reverse)