First among the causes of distress during this unhappy period must be placed the Navigation Acts. England, in the middle of the 17th century, was engaged in an unsuccessful contest with Holland for the carrying trade of the world. The merchantmen of Amsterdam and Flushing found their way even to Maryland and Virginia, where their low freight rates and the liberal prices they gave for tobacco, assured them a hearty welcome. The exports of the colonies to England itself were not infrequently carried in Dutch bottoms. This was a source of much anxiety and annoyance to the British government. It seemed unjust that the American colonies, which had been founded at such tremendous cost, should now prove as great a source of wealth to Holland as to the mother country. And it could not but anger the English shippers to find themselves elbowed by these foreigners in the ports of the Bermudas or the rivers of Virginia. In 1651, the British Parliament, thinking it necessary to give their merchants some protection from this lively competition, passed the first of the Navigation Acts. Under its provisions no goods of the growth or manufacture of Asia, America or Africa should be introduced into England in any but English ships, of which the owner, master and three-fourths of the sailors were English subjects; and all foreign commodities imported to England should be conveyed directly thither from the place of growth or manufacture.[382] This law injured the Virginians by excluding the Dutch carriers from the tobacco trade with England and thus causing a sharp rise in freight rates. During the early years of the Commonwealth period it was frequently avoided, but before 1660 the English government began to enforce it more strictly. Nor did the people get relief with the restoration of the monarchy. Charles II proved more solicitous that Parliament for the welfare of the English merchants; even more indifferent to the complaints of the colonists. A new Navigation Act was passed in 1660 which struck a deadly blow at the prosperity of Virginia. Under its provisions all goods sent to the colonies, even though of foreign growth or manufacture, were to be exported from England, and all tobacco, sugar, wool, etc., produced in the colonies, must be shipped only to England or to her dominions.[383]