By the conquest of Portugal in 1580 her king had acquired control over the East Indies, which were hardly less valuable than the colonies of Spain; and with the money derived from both the Spanish and Portuguese possessions Philip supported his armies in Italy and the Netherlands, and was the mainstay of the pope at Rome, the Guises in France, and the secret plotters in Scotland and Ireland of rebellion against the authority of Elizabeth.
This wide distribution of power was, however, an inherent weakness which created demands enough to exhaust the treasury even of Philip, and he instinctively recognized in England a danger which must be promptly removed.

England must be subdued, and Philip, determining on an invasion, collected a powerful army at Bruges, in Flanders, and an immense fleet in the Tagus, in Spain.

For the attack he selected a time when Amsterdam, the great mart of the Netherlands, had fallen before his general the duke of Palma; when the king of France had become a prisoner of the Guises; and when the frenzied hatred of the Catholic world was directed against Elizabeth for the execution of Mary, queen of Scots.
How to meet and repel this immense danger caused many consultations on the part of Elizabeth and her statesmen, and at first they inclined to make the defence by land only.

But Raleigh, like Themistocles at Athens under similar conditions, urgently advised dependence on a well-equipped fleet, and after some hesitation his advice was followed.

Then every effort was strained to bring into service every ship that could be found or constructed in time within the limits of England, so that in May, 1588, when Philip's huge Armada set sail from the Tagus, a numerous English fleet was ready to dispute its onward passage.