In 1588, the year of the Spanish Armada, Stanley was at the head of 700 men in the Netherlands, ready to embark with the invasion fleet. After the failure of the Armada, Sir William Fitzwilliam, lord deputy of Ireland, speculated that Stanley might be chosen to lead the Spanish army in any further attempt to invade England. In any event, he maintained his regiment in the Netherlands while travelling often to Spain to urge action against Elizabeth. Stanley drew up plans for the conquest of Alderney in the late 1580s, but these too were cast aside by the Duke of Parma. Philip II remained obstinate in his refusal to deploy the English regiment outside the Low Countries.