The revolutionary party had now done its work effectually in the domestic field of battle. Its enemies, as far as the navy was concerned, were in future to be foreigners. There was no doubt, even before the end of 1651, who the main enemy would be. At that time there was but one possible opponent at sea for England, the United States of the Netherlands. War had been preparing between them for some time, and very little was wanted to bring it on. The passing of the Navigation Act in 1651 was of itself an almost sufficient cause for hostilities. The policy which this law was designed to enforce was not in itself new. As far back as the reign of Henry VII., laws had been passed to support English shipping against foreign competition, but they had either been ill enforced, or ill calculated to secure their purpose. The Navigation Act of 1651 was directed against the carrying trade of Holland, with avowedly hostile intentions. It was drafted for the express purpose of ruining the Dutch shipping as far as we were concerned, by forbidding the importation of goods into England, except in ships belonging to the nation which produced them, or in English vessels. This of itself might not have led to open conflict between the two countries, but there were other causes of hostility. The rivalry of the English and Dutch at sea had not always been peaceful. In the early days of the century the East India Companies of the two countries had combined to assert their right of trading with the East in defiance of the Portuguese. When their feeble opponent had been overcome, a task very easily effected, they had fallen out with one another. The chief scene of their conflict had been in the islands of the Indian Ocean, and the victory had remained with the Dutch, who made these the seat of their Eastern Empire. The most notorious incident of the expulsion of the English from the region which the Dutch desired to reserve to themselves, was the massacre of Amboyna, an island near the Moluccas, in 1623. By the terms of a treaty made in 1619 between England and the United Provinces, it had been agreed that the two nations were to live in peace in these regions, and that their respective factories were to share the trade. According to the English account, which is certainly supported by probability, the Dutch vamped up an accusation of treason against the English factors (_i.e._ commercial agents) at Amboyna. Under the pretence that they had entered into a plot with the Japanese to massacre their Dutch allies, they were suddenly attacked, thrown into prison, and tortured with abominable cruelty. Then, taking advantage of this supposed discovery of a plot, the Dutch made it a pretext to expel the English factories from the whole of the Spice Islands. During thirty years the memory of the massacre of Amboyna had remained fresh with the English. The Governments of James I. and Charles I. had made several attempts to obtain satisfaction by