Until the middle of the 17th century, English overseas trade was negligible. Spanish and Dutch merchants dominated the markets in Europe and across the Atlantic, and controlled imports of goods into England from the Levant, the Spanish and Portuguese empires, and the West Indies.
In 1651, however, Oliver Cromwell's Parliament took steps to block and weaken the primacy of the Dutch who were acting as a kind of 'storehouse' for goods from all over the world, and were running a highly lucrative carrying trade to England and elsewhere in Europe. New regulations were put in place - the Navigation Ordinances - which effectively prevented the Dutch from having any part in England's import trades. From now on only English shipping could convey foreign goods to England.
After the restoration of Charles II, Parliament continued this policy of protecting English trade. In new legislation passed in 1660, 1662 and 1663 trade between England and her colonies was effectively limited to English (or colonial) shipping.
Under 18th century legislation, certain colonial exports, such as sugar, rice and tobacco, had to be shipped first to England before they could be re-exported to European ports. Duties were usually payable when the goods were landed in England, and a 'drawback' was paid when re-exported. Legislation easing these cumbersome practices was passed in the 1730s and merchants were allowed to store items, temporarily, free of duty.
The 'Navigation Laws' provided a structure of protection for trade that lasted until the middle of the 19th century. After the union of England and Scotland in 1707 and the establishment of Great Britain, Scottish trade was also brought within their scope. Although Ireland remained formally excluded under the Navigation Acts, Irish merchants were nevertheless active in trading many goods with the American colonies.