Not only were rebels supported, not only were Spanish fleets taken forcibly into English harbors and there stripped of moneys belonging to their government, but refugees were protected and Spanish citizens put to death by the English queen.

Philip and Alva could not effectively resent and hardly dared to protest against the treatment, because they felt themselves powerless.

As so often, the island kingdom was protected by the ocean and by the proved superiority of her seamen.
After a score of petty fights all the way from the Bay of Biscay to the Pacific Ocean, Spanish sailors had no desire for a trial of strength in force.
But in every respect save in sea power Spain felt herself immeasurably superior to her foe.

Her wealth, her dominions, recently augmented by the annexation of Portugal, were enormous; her army had been tried in a hundred battles.

England's force was doubtless underestimated.