The naval power of Holland had been necessary to her during the war of religion in which Spain had tried to crush out the Protestant spirit. As early as 1607 the Dutch fleet had practically destroyed the principal fleet of Spain off Gibraltar. The Dutch, as we have seen, had taken the supremacy which the Portuguese had held in the Malay Archipelago; and since Portugal till 1640 had been for sixty years under the King of Spain, it was nearly equivalent to taking that supremacy from Spain herself. The victory which really was decisive was won by the great Dutch admiral, Van Tromp, in 1639. It made Holland, so lately a mere province of Spain, the strongest sea-power in the world. [Sidenote: Cromwell as dictator] And at this point, that is to say, in 1651, Cromwell, in his masterful manner, passed the law called the Navigation Act which directly challenged the naval power of Holland. It provided that ships trading to England should carry no other goods than those produced in the country to which the ship belonged; and this was a direct challenge to the Dutch because they had a great carrying trade, and their ships brought to England the goods produced in many other countries besides their own. Moreover, the English claimed that the ships of all other nations meeting English ships in the Channel, should salute them by lowering their flags. The English admiral, Blake, meeting the Dutch fleet under Van Tromp in the Channel, demanded that he should lower the Dutch flag accordingly, and Van Tromp's reply was a broadside from his guns. As always, the English seamen fought with astonishing {91} skill and courage. Probably in the whole course of this Greatest Story only one other nation, and that the Dutch, has rivalled them in their genius for the battle at sea. After several actions the issue was still open. Van Tromp swept the Channel for a while, after an English defeat, splicing a broom, by way of derision, to his masthead. But the English fleet was strengthened; Blake came forth again from the Thames and harried Van Tromp successfully. While Cromwell was Protector neither side had the decisive mastery. The day of England's humiliation was to come later, when a Dutch fleet sailed up the Thames and burned English ships at Chatham; but that was not until again a weak Stuart was on the throne.