<human>:  When did the Spanish Armada sail?
<bot>: The Spanish Armada was a fleet of warships sent from Spain to England in 1588. It was the largest naval force to be assembled in Europe since the days of the Roman Empire. It was led by the Duke of Medina Sidonia, but he was replaced by the Duke of Parma after the fleet had left Spain. The Armada was intended to invade England and overthrow Elizabeth I, but it was defeated at the Battle of Gravelines by the English navy.