This national holiday is celebrated annually on 21 July.
Independence Day celebrates the separation of Belgium from the Netherlands in 1831, as well as the formal establishment of the Kingdom.
Belgium had been part of the United Kingdom of the Netherlands since 1815, but the majority of the population were Roman Catholic and increasingly felt the rule of King William I favoured the Northern protestants. The discontentment was heightened by high levels of unemployment in the South.
In August 1830, riots led to a wider uprising and calls for Belgium to succeed from the Netherlands. A London Conference of major European powers then recognized Belgian independence
After Belgium asserted its independence from the Netherlands on 4th October 1830, the Belgian National Congress considered several candidates to become king.
After deliberation, they asked Leopold I of Saxe-Coburg to become king of the newly formed country. Leopold accepted and was proclaimed "King of the Belgians" on 26th June 1831.
He swore allegiance to the constitution in the Royal Palace in Brussels on 21st July 1831.
This day became the Belgian national holiday.