the city was liberated on October 3rd. 1574.
Source picture: Wikipedia
During the 'Eighty Year's War' Dutch rebels took their arms against the Spanish
King Philip II, who appointed the Duke of Alba to beat this rebels.
The Duke of Alba, who was governor general of the Spanish Netherlands,
had the bad reputation to be violent.
To preserve their religious freedom, Leiden sworn allegiance to
Prince William of Orange in 1572.
Of course, the Duke of Alba wanted to force this rebellious city to
surrender. He started the Siege of Leiden in 1573. After several battles
and due to the weather, the Spanish troops had to flee.
As a special thanks for the resistance of the city, the University of Leiden
was founded in 1575 by Prince William of Orange.
The October 3rd. remembrance festival is celebrated every year in Leiden.
I made a previous blog post about Leiden. You can check the post
on this link