The Battle of Gravelines, the decisive battle of the Spanish Armada, took place off the coast of Flanders.
In May 1588, King Philip II of Spain sent a fleet of 130 ships under the command of the Duke of Medina Sidonia to support the invasion of England by 30,000 troops based in the Spanish Netherlands. Their objective, which had the support of Pope Sixtus V, was to overthrow Elizabeth I and reinstate Catholicism.
Elizabeth was expecting an invasion attempt, so had sent Sir Francis Drake to the Bay of Cádiz the previous year to disrupt the Spanish preparations. By the time the Armada set sail in 1588 the English fleet, based in Plymouth, outnumbered the Spanish but had lower overall firepower.
Harried by the English, the Armada sailed along the English south coast and reached Calais on 27 July where the fleet anchored in a defensive crescent formation. At midnight the next day the English sent ships packed with wood and pitch and set alight directly into the middle of the Spanish fleet which resulted in the ships scattering and breaking the crescent formation.
With the Spanish fleet in disarray, the English closed for battle on 29 July. They repeatedly provoked the Spanish, and then used the wind to sail out of range of their guns before closing in again to unleash a broadside. In this manner the Spanish were gradually worn down, losing five ships while sinking none of the English.
Having run dangerously low of ammunition, Medina Sidonia took advantage of a change in the wind and fled north. Chased by the English fleet, the Armada was forced to sail around the north coast of Scotland and return to Spain via Ireland. Less than half the ships that had set out made it back.