The seventeenth century was the crisis in the career of the Mercantile Marine, for it was struggling for its very life amid many dangers, but it emerged with an independence and character of its own. In any long period of assured peace it reaches enormous heights of success, as, for instance, during the nineteenth century. But during the Caroline period a principle was being insisted upon. The position was this. Charles I was determined to compel the Dutch to acknowledge the English claim to the dominion of the seas, and that was the reason for the building, in 1637, of that marvellous and sensational warship the _Sovereign of the Seas_, a triumph of Pett’s design, which Van der Velde depicted for posterity. This 1683-ton “battleship,” as we should call her nowadays, was an expression, both in name and character, of the English attitude in regard to the use of the seas. “We hold it a principle,” Charles had instructed his Minister at The Hague, “not to be denied, that the King of Great Britain is a monarch at sea and on land to the full extent of his dominions. His Majesty finds it necessary for his own defence and safety to reassume and keep his ancient and undoubted rights in the Dominion of the Seas.” Having forbidden foreigners to fish off our coasts without licence, Charles’ fleet attacked and put to flight a Dutch fishing fleet which had infringed this order. Some of these small craft were thus sunk by our men-of-war, and many of the rest took shelter in harbour. Finally the Dutch agreed to pay Charles I £30,000 for permission to finish that year’s fishing, and to pay a sum annually for the like privilege. We can well understand the irritation which this line of action caused so great a maritime power as the Dutch. Great sea pioneers they certainly were, and before the first decade after the defeat of the Armada had passed, they had been the first country to send out a real Polar expedition. In 1651 came the celebrated English Navigation Act, which prohibited the importation of goods into England except in English ships, or in the ships of the country producing the goods. This was quite obviously aimed at the great Dutch sea-carriers. Relations became strained, the war-clouds gathered, and in the following year the first of the three Anglo-Dutch wars broke out inevitably between the English and Dutch republics.