In 1579 the city of Maastricht was in the hands of the Dutch rebels. On March 12, 1579 the Spanish General Alexander Farnese started to lay siege to the city with his army consisting of 20,000 men. The Dutch garrison consisted of 2,000 soldiers and some city militia.
The Spanish commander ordered his troops to sap the walls. The inhabitants of Maastricht too were digging to reach the Spanish tunnels. Deep under ground the fighting continued, hundreds of Spanish soldiers died as boiling water was poured into their tunnels. Others died because of a lack of oxygen when the Dutch defenders ignited fires within them. Another 500 Spanish soldiers died when a mine, which they planned to use to blow up the wall, exploded prematurely.
In the night of 29 June Farnese managed to get into the city while the exhausted defenders were fast asleep. The Spanish looted the city for 3 days.