146 THE PORTUGUESE POLICY IN THE EAST inflicted for resistance. The whole coast of Asia from the Eed Sea to the Eastern Archipelago was thus men- aced by an invisible foe from the ocean, whose move- ments defied calculation, whose attack was often irre- sistible, and whose vengeance always cruel. No such fleets had ever been seen in Asia, and the Portuguese treaties took care that none should grow up. As Por- tugal never acquired inland territories in India proper, and as her possessions were mainly confined to patches on the seaboard, this system sufficed for their defence long after her military vigour had declined. But its effectiveness depended on the absence of any other naval force; and when the maritime nations of northern Europe broke in upon the Indian Ocean, the Portuguese power collapsed. It would be wrong, however, to underrate either the skill or the heroism with which their sea-power was built up. From the orders of King Emmanuel in 1514 for an examination of the ports, anchorages, and dis- tances in the Red Sea and Persian Gulf, marine survey- ing dates in Asia. In spite of discrepancies in the results, a mass of material was collected during the next century, and geographical names attest the exploring activity of Portugal from the coast of Africa to China and Japan. The knowledge thus acquired was put to good use for purposes of strategy. The Portuguese found they could command the whole Asiatic trade- route by squadrons at three points on its course the outlet of the Red Sea, the passage round Ceylon, and the Straits of Malacca. When Aden, which would be
