Background
The Spanish Armada was the culmination of two decades of accumulating conflict between Spain and Elizabethan England. The conflict had three principal dimensions: religious (the Reformation had divided Catholic Spain from Protestant England; Pope Pius V had excommunicated Elizabeth I in 1570; English execution of the Catholic Mary Queen of Scots in February 1587 was a final provocation), commercial (English privateers — Francis Drake, John Hawkins, others — had been raiding Spanish shipping and Spanish American ports for two decades), and strategic (English military and financial support for the Dutch Protestant revolt against Spanish rule had committed the two countries to open warfare from 1585 onward).
Philip II of Spain ordered the preparation of an invasion fleet in 1586. The plan was complex: the Armada would sail from Lisbon up the English Channel, meet the Spanish Army of Flanders (approximately 30,000 troops under the Duke of Parma) at Calais or Dunkirk, escort the army across the Channel, land it on the Kent coast, and capture London. The combined operation was the largest single Spanish military effort of the 16th century.
Preparation
The Armada took two years to assemble. Sir Francis Drake’s pre-emptive raid on Cádiz in April 1587 destroyed approximately 30 Spanish ships and substantial stores of seasoned timber, delaying the invasion by approximately a year (Drake called it “the singeing of the King of Spain’s beard”). The Armada’s original commander, the Marqués de Santa Cruz, died in February 1588; Philip replaced him with the Duke of Medina Sidonia, an experienced administrator with limited naval combat experience.
The final Armada that sailed from Lisbon on 30 May 1588 consisted of approximately 130 vessels: 28 first-line warships (mostly Portuguese galleons inherited by the Spanish Crown in 1580), approximately 40 armed merchantmen (urcas), and the supply and transport fleet. It carried approximately 19,000 soldiers, 7,000 sailors, 180 priests, and supplies for an extended campaign.
The campaign
The Armada was sighted off the Lizard, in southwestern Cornwall, on 29 July 1588. English coastal beacons relayed the news to London within hours. The English fleet under Lord Howard of Effingham (with Drake as vice-admiral) put to sea from Plymouth in the early morning of 30 July.
The English and Spanish fleets fought a running engagement up the Channel over the following week. The Spanish ships were larger and carried more troops; the English ships were smaller, faster, and more heavily armed with longer-range guns. Spanish tactics required boarding actions to fight at advantage; English tactics required keeping range and using superior gunnery. The running engagement of 31 July – 6 August produced minimal direct damage but exhausted Spanish ammunition and prevented the Armada from forming a tight defensive formation.
Medina Sidonia anchored the Armada off Calais on the evening of 6 August, waiting for Parma’s army to embark from Dunkirk. Parma was not ready; his troop barges were not assembled and the Dutch rebel fleet was blockading Dunkirk’s harbour. The Armada was anchored in an exposed roadstead with no clear next step.
The English sent eight fireships — burning vessels filled with combustibles — into the anchored Armada on the night of 7–8 August. The Spanish ships cut anchor cables to avoid the fires, scattered north into the North Sea, and could not re-form into defensive order before the English fleet caught them in open water.
The Battle of Gravelines (8 August 1588) was the decisive engagement. The English fleet engaged the now-disorganized Armada at close range for nearly the full day, sinking several Spanish ships and damaging many others. By evening the surviving Armada was being blown northeast into the North Sea by a stiff southwest wind and had lost the operational ability to re-engage.
The return voyage
The Armada could not return to Spain via the Channel; the English fleet blocked the route. Medina Sidonia ordered the Armada to sail north around Scotland and Ireland and return to Spain via the North Atlantic. The decision was navigationally reasonable but tactically catastrophic. The Armada had inadequate North Atlantic charts, poor provisions, ships damaged from the Channel fighting, and unfavourable weather.
Approximately 24 to 35 Spanish ships were wrecked on the Scottish and Irish coasts in storms during August–September 1588. Survivors who reached shore in Ireland were mostly killed by English colonial authorities or local populations. Approximately 65 ships eventually returned to Spain, but many of them in damaged or unrepairable condition. Total losses are estimated at approximately 50 ships and 15,000 men — overwhelmingly to weather, disease, and shipwreck rather than to English combat.
Consequences
The Armada’s failure did not end Anglo-Spanish warfare; the war continued until 1604, and English counter-invasions of Spain (the 1589 English Armada under Drake and Norris) were equally unsuccessful. The campaign did secure the Elizabethan religious-political settlement against external invasion, establish English naval reputation across Europe, and provide the political-cultural moment around which Elizabethan national identity consolidated.
The Armada also produced one of the earliest moments of European naval combat in which gunnery rather than boarding action proved decisive — a transition that would dominate European naval combat for the next three centuries. The English deliberate construction of fast, heavily-gunned, agile warships proved more effective against the high-sided Spanish galleons than the boarding-action tactics those galleons were designed to support.
The Armada’s wreck sites have been substantially mapped by modern archaeology. Several wrecks on the Irish and Scottish coasts (most notably La Trinidad Valencera off Donegal and La Girona off Antrim) have produced extensive recovered material now distributed across Irish, Scottish, and Spanish museums.