Elizabeth I ordered the attack on the Spanish Port of Cadiz in the March of 1587. Francis Drake sailed with his fleet into Cadiz harbour on 19th April 1587 and over the next few days destroyed around 30 ships and caused damage to the provisions for the Armada. After the attack Drake raided ports along the Portuguese Coast before sailing out into the Atlantic to raid Spanish treasure galleons.  

Drake’s raid set the Armada back by about a year, and ultimately gave England more time to prepare for the eventual attack by the Spanish in 1588.