The Spanish Armada (Old Spanish: Grande y Felicísima Armada, "Great and Most Fortunate Navy") was the Spanish fleet that sailed against England under the command of the Duke of Medina Sidona in 1588.
The Armada was sent by King Philip II of Spain, who had been king consort of England until the death of his wife Mary I of England thirty years earlier. The purpose of the expedition was to escort the Duke of Parma's army of tercios from the Spanish Netherlands across the North Sea for a landing in south-east England. Once the army had suppressed English support for the United Provinces — part of the Spanish Netherlands — it was intended to cut off attacks against Spanish possessions in the New World and the Atlantic treasure fleets. It was also hoped to reverse the Protestant Reformation in England, and to this end the expedition was supported by Pope Sixtus V, with the promise of a subsidy should it make land. The command of the fleet was originally entrusted to Alvaro de Bazan, a highly experienced naval commander who died a few months before the fleet sailed from Lisbon in May 1588.
The Armada consisted of about 130 warships and converted merchant ships. After forcing its way up the English Channel, it was attacked by a fleet of 200 English ships, assisted by the Dutch navy, in the North Sea at Gravelines off the coastal border between France and the Spanish Netherlands. A fire-ship attack drove the Armada ships from their safe anchorage, and in the ensuing battle the Spanish abandoned their rendezvous with Parma's army.
The Armada was blown north up the east coast of England and in a hasty strategic move, attempted a return to Spain by sailing around Scotland and out into the Atlantic, past Ireland. But very severe weather destroyed a portion of the fleet, and more than 24 vessels were wrecked on the north and western coasts of Ireland, with the survivors having to seek refuge in Scotland. Of the Armada's initial complement of vessels, about 50 did not return to Spain. However, the loss to Philip's Royal Navy was comparatively small: only seven ships failed to return, and of these only three were lost to enemy action.
The expedition was the most significant engagement of the undeclared Anglo–Spanish War (1585–1604). Centuries of British literature perpetuated many myths about the event, treating it as a swing in naval dominance towards the English at the expense of the Spanish. In fact, modern scholarship presents it as the beginning of an increase in Spanish naval supremacy, which started to be reversed arguably during the Thirty Years War and most likely in the early part of the 19th century.