6. =The Navigation Act. 1651.=--Ever since the days of James I. there had existed a commercial rivalry between England and the Dutch Republic, and disputes relating to trade constantly arose. Latterly these disputes had been growing more acute. Early in =1648= Spain came to terms with the Dutch by acknowledging their independence, and, later in the same year, the Thirty Years' War in Germany was brought to an end by the Peace of Westphalia, though war between France and Spain still continued. Henceforth religion was no longer made the pretext for war on the Continent; and States contended with one another because they wished either to annex territory, or to settle some trade dispute in their own favour. In =1650= the Stadholder, William II.--the son-in-law of Charles I.--died, and the office which he held was abolished, the government of the Dutch Republic falling completely under the control of the merchants of the Province of Holland, in which were situated the great commercial ports of Amsterdam and Rotterdam. The Dutch had got into their hands the carrying trade of Europe. In =1651= the English Parliament passed the Navigation Act, to put an end to this state of things. English vessels alone were to be allowed to import goods into England, except in the case of vessels belonging to the country in which the goods which they carried were produced. 7. =The Dutch War. 1652-1653.=--War with the Dutch soon followed. Vane, the leading man in the Committee of the Council of State which managed the navy, had put the fleet into excellent condition. Its command was given to Blake, who had been noted as a soldier by the defence of Taunton (see p. 547) in the Civil War, but who never went to sea till =1649=, when he was over fifty. Yet Blake soon found himself at home on board ship, and won the confidence of officers and men. Battle after battle was fought between the English and Dutch fleets. The sturdy antagonists were well matched, though the English ships were larger and more powerfully armed. In November =1652=, Tromp (the Dutch Admiral) got the better of Blake, but in February =1653= there was another battle, in which Blake got the upper hand; but it was no crushing victory, like Dunbar and Worcester. In the summer of =1653= the English gained two more victories, but though they attempted to blockade the Dutch ports, they were obliged to give up the attempt.