The king of Spain at this time, King Philip II, had been king consort of England until the death of his wife Queen Mary I of England in 1558 (also known as “Bloody Mary” for the many religious dissenters she burned at the stake – she reinstituted Roman Catholicism in England), and he wasn’t a fan of the policies pursued by her successor, Queen Elizabeth I, his sister-in-law. The aim of his expedition was to invade and conquer England, thereby ending attacks on Spanish possessions in the New World and weakening support for Dutch-controlled provinces in the Spanish Netherlands. The king was supported by Pope Sixtus V (who had renewed Elizabeth’s excommunication from the Roman Catholic Church), who treated the invasion as a crusade, and promised money should the Armada make land.
The intention was to set out from Spain and meet with more ships off the coast of Flanders, mustering an army of altogether 55,000 men, a huge amount for the time. However the English drove the Spanish from the coast of the Netherlands before they met the second fleet, and eventually forced the Spanish to retreat. Though they planned on returning to Spain, the Spanish were driven off course by severe storms, wrecking many of their ships on the Irish coast. In the end, only 67 ships and around 10,000 men survived.
The defeat of the Spanish Armada strengthened the Protestant cause across Europe and suggested that God was on their side.