The Anglo–Spanish War (1585–1604) was an intermittent conflict between the kingdoms of Spain and England that was never formally declared. The war was punctuated by widely separated battles, and began with England's military expedition in 1585 to the Netherlands under the command of the Earl of Leicester in support of the resistance of the States General to Habsburg rule.
The English enjoyed major victories at Cádiz in 1587, and over the Spanish Armada in 1588, but gradually lost the initiative after the severe defeats of the English Armada in 1589 and the Drake–Hawkins and Essex–Raleigh expeditions in 1595 and 1597 respectively. Two further Spanish armadas were sent in 1596 and 1597 but were frustrated in their objectives because of adverse weather.
The war became deadlocked around the turn of the 17th century during campaigns in Brittany and Ireland. It was brought to an end with the Treaty of London, negotiated in 1604 between representatives of the new king of Spain, Philip III, and the new king of England, James I. England and Spain agreed to cease their military interventions in the Spanish Netherlands and Ireland, respectively, and the English ended high seas privateering.