The siege of Haarlem was an episode of the Eighty Years' War. From 11 December 1572 to 13 July 1573 an army of Philip II of Spain laid bloody siege to the city of Haarlem in the Netherlands, whose loyalties had begun wavering during the previous summer. After the naval battle of Haarlemmermeer and the defeat of a land relief force, the starving city surrendered and the garrison was massacred. The resistance nonetheless was taken as an heroic example by the Orangists at the sieges of Alkmaar and Leiden.

The Eighty Years' War (Dutch: Tachtigjarige Oorlog; Spanish: Guerra de los Ochenta Años) or Dutch War of Independence (1568–1648) was a revolt of the Seventeen Provinces of what are today the Netherlands, Belgium and Luxembourg against Philip II of Spain, the sovereign of the Habsburg Netherlands. After the initial stages, Philip II deployed his armies and regained control over most of the rebelling provinces. Under the leadership of the exiled William the Silent, the northern provinces continued their resistance. They eventually were able to oust the Habsburg armies, and in 1581 they established the Republic of the Seven United Netherlands. The war continued in other areas, although the heartland of the republic was no longer threatened. This included the origins of the Dutch colonial empire, which began with Dutch attacks on Portugal's overseas territories. At the time, this was conceived as carrying the war with the Spanish Empire overseas due to Portugal and Spain's being in a dynastic union.

The Dutch Republic was recognised by Spain and the major European powers in 1609 at the start of the Twelve Years' Truce. Hostilities broke out again around 1619, as part of the broader Thirty Years' War. An end was reached in 1648 with the Peace of Münster (a treaty part of the Peace of Westphalia), when the Dutch Republic was definitively recognised as an independent country no longer part of the Holy Roman Empire. The Peace of Münster is sometimes considered the beginning of the Dutch Golden Age. Nevertheless, despite achieving independence, from the end of the war in 1648 there was considerable opposition to the Treaty of Münster within the States General of the Netherlands since it allowed Spain to retain the Southern Provinces and permitted religious toleration for Catholics.