This public holiday is El Salvador's National Day and is always celebrated on 15 September. It commemorates the independence of the Central American provinces from Spanish rule in 1821.
The Spanish Admiral Andrés Niño led an expedition to Central America in 1522. He discovered Jiquilisco Bay on the mouth of Lempa River. This was the first known visit by Europeans to what is now Salvadoran territory.
A few years later, Spanish Conquistadors led by Pedro de Alvarado and his brother Gonzalo arrived what is now the Republic of El Salvador. They were disappointed to find the area wasn't rich in gold, but the quality of its soil was noted. The indigenous people put up stiff resistance to the Spanish and it was 1525 become the area finally fell under Spanish control.
It was Pedro de Alvarado who named El Salvador after Jesus Christ, the Saviour.
In 1609, El Salvador became part of the Kingdom of Guatemala, which included the present-day nations of Costa Rica, Nicaragua, El Salvador, El Salvador and Guatemala, and the Mexican state of Chiapas.
Spain had been weakened by its involvement in the Peninsular War in Europe and local juntas had been created as local Spanish had revolted against the rule of King Joseph, Napoleon's brother who had been installed as ruler of Spain by the French.
This taste for independent rule was keenly felt in El Salvador. The 1811 Independence Movement became known in El Salvador as the Primer grito de independencia (the First shout of Independence).
On 15 September 1821, the Act of Independence of Central America was declared by the Province of Guatemala.
Following independence and despite opposition from El Salvador, the regions became part of the Mexican Empire, until they ceded to become the Federal Republic of Central America in 1823.