Against which country did the Dutch Republic fight the Eighty Years' War?

The story behind the answer

Spain is correct: the Eighty Years’ War (1568–1648) was the Dutch revolt against Habsburg Spain under Philip II, sparked by heavy taxation, centralization, and repression of Protestant (Calvinist) worship. After decades of struggle—led early by William of Orange—the northern provinces formed the Dutch Republic, whose independence Spain finally recognized in 1648 (Peace of Münster/Westphalia).

Context to remember: the Low Countries were then called the Spanish Netherlands—an easy cue that Spain was the ruler the Dutch fought. The conflict fostered Dutch naval power and trade, helping launch the Dutch Golden Age. Quick mnemonic: Three S’s—Spain, Spanish Netherlands, States-General—signal the Spanish crown the Dutch opposed.