This Act decreed that no production of Asia, Africa or America should be brought to England, except in English vessels, manned by English crews, and that no productions of Europe should be brought to England, unless in English vessels, or in those of the country in which the imported cargoes were produced. These measures were considered very unjust by all the other nations, and especially by the Dutch, then the most commercial nation on the globe. The States-General sent ambassadors to London to remonstrate against such hostile action; and at the same time orders were issued for the equipment of one hundred and fifty ships of war. The States-General had not yet ratified Stuyvesant's treaty of Hartford. The ambassadors were instructed to urge that an immovable boundary line should be established between the Dutch and English possessions in America. The reply of the English Government was not conciliatory. The English, it was said, had always been forbidden to trade in the Dutch colonies. The Dutch ought therefore to find no fault with the recent Navigation Act, from which measure the Council did not "deem it fitting to recede." As to the colonial boundary, the ungracious reply was returned, "The English were the first settlers in North America, from Virginia to Newfoundland. We know nothing of any Dutch plantations there, excepting a few settlers up the Hudson. We do not think it necessary at present, to settle the boundaries. It can be done hereafter, at any convenient time." A naval war soon broke out. England, without warning, seized the ships of Holland in English ports, and impressed their crews. The Dutch war fleet was entrusted to Admiral Tromp. He was enjoined to protect the Dutch vessels from visitation or search by foreign cruisers, and not to strike his flag to English ships of war. The instructions of the commanders of the British men of war, were to compel the ships of all foreign nations whatever, to strike their colors to the British flag. England thus set up its arrogant claim to "its undoubted right to the dominion of the surrounding seas." The English fleet, under Admiral Blake, met the Dutch fleet in the Strait of Dover, on the 29th of May, 1632, and a bloody but undecisive battle ensued. A series of terrible naval conflicts followed, with victory now on the one side and now on the other. At length Blake, discomfited, was compelled to take refuge in the Thames. Admiral Tromp, rather vain-gloriously, placed a broom at his masthead to indicate that he had swept the channel of all English ships. In this state of affairs the Directors wrote to Governor Stuyvesant, saying,