The siege of Sluis took place during the Eighty Years' War, a protracted conflict between the Dutch Republic and Spanish rule over the Netherlands. Sluis, a strategic port city located in Flanders, was under the control of Spanish forces. The city had become a focal point in the war, with its capture seen as crucial by both the Dutch and Spanish sides. Maurice of Nassau, Prince of Orange, recognized the importance of Sluis to disrupt Spanish supply lines and improve Dutch naval capabilities in the region.

Maurice's army combined Dutch forces with English support, reflecting the alliances formed during this period of conflict. The siege employed advanced military techniques including trench warfare and artillery bombardment, which were relatively new tactics at the time. The coordination between Dutch and English forces was essential, as they schemed to create a blockade and cut off supplies to the garrison. After several weeks of intense fighting, the Spanish defenders, recognizing the inevitability of their situation, opted to surrender.

The surrender of Sluis not only boosted the morale of the Dutch and their allies but also served as a strategic advantage in the ongoing war. It showcased Maurice of Orange's military prowess and further established his reputation as a capable leader. The loss of Sluis was a significant blow to Spanish control in the region, as it allowed the Dutch to expand their naval operations in the North Sea and disrupt Spanish trade routes. This victory had lasting implications for the war and the balance of power in Europe.