Following the Belgian revolution of 1830, which led to the independence of Belgium, the National Congress decided that Belgium should be a constitutional monarchy. On June 4, 1831, the Congress calls Leopold of Saxe-Coburg-Gotha (by 153 votes out of 196), to become the first king of the Belgians.
On July 17, the king went from England to Calais by boat and then by horse-drawn carriage by the beach of Dunkirk until De Panne. He then went to the Place Royale in Brussels where he was sworn in on 21 July 1831 and became the first King of the Belgians. The day of the national holiday was first fixed on September 27th, then commemorating the "September Days", a name commonly given to the Belgian Revolution. It was not until the reign of Leopold II, May 27, 1890, that the national holiday was set for July 21 to link this day of celebration for the country to the person of the King.