Anglo-Spanish War (1585–1604)  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 what was then the Spanish Netherlands under the command of Robert Dudley, Earl of Leicester in support of the resistance of the States General to Spanish Habsburg rule. The English enjoyed significant victories at Cádiz in 1587, and destroyed a large portion of the Spanish Armada before forcing it to retreat the very next year, but then suffered setbacks in 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 these ended in defeats for Spain mainly because of adverse weather and poor planning. The war became deadlocked around the turn of the 17th century during campaigns in the Netherlands, France 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. In the 1560s, Philip II of Spain was faced with increasing religious disturbances as Protestantism gained adherents in his domains in the Low Countries. As a defender of the Catholic Church, he sought to suppress the rising Protestant movement in his territories, which eventually exploded into open rebellion in 1566. Meanwhile, relations with the regime of Elizabeth I of England continued to deteriorate, following her restoration of royal supremacy over the Church of England through the Act of Supremacy in 1559; this had been first instituted by her father Henry VIII and rescinded by her sister Mary I, Philip's wife. The Act was considered by Catholics as a usurpation of papal authority. Calls by leading English Protestants to support the Protestant Dutch rebels against Philip increased tensions further as did the Catholic-Protestant disturbances in France, which saw both sides supporting the opposing French factions. Complicating matters were commercial disputes. The activities of English sailors, begun by Sir John Hawkins in 1562, gained the tacit support of Elizabeth, even though the Spanish government complained that Hawkins's trade with their colonies in the West Indies constituted smuggling. In September 1568, a slaving expedition led by Hawkins and Sir Francis Drake was surprised by the Spanish, and several ships were captured or sunk at the Battle of San Juan de Ulúa near Veracruz in New Spain.