The Navigation Acts were a series of English laws that restricted colonial trade to England. They were first enacted in 1651 and throughout that time until 1663, and were repealed in 1849. They reflected the policy of mercantilism, which sought to keep all the benefits of trade inside the Empire, and to minimize the loss of gold and silver to foreigners. They prohibited the colonies from trading directly with the Netherlands, Spain, France, and their colonies. The original ordinance of 1651 was renewed at the Restoration by Acts of 1660, 1663, 1670, and 1673, with subsequent minor amendments. The Acts formed the basis for English overseas trade for nearly 200 years. Additionally the Acts restricted the employment of non-English sailors to a quarter of the crew on returning East India Company ships.
The major impetuses for the Navigation Acts were the ruinous deterioration of English trade in the aftermath of the Eighty Years' War, and the concomitant lifting of the Spanish embargoes on trade between the Spanish Empire and the Dutch Republic. The end of the embargoes in 1647 unleashed the full power of the Amsterdam Entrepôt and other Dutch competitive advantages in world trade. Within a few years, English merchants had practically been overwhelmed in the trade in the Iberian Peninsula, the Mediterranean and the Levant. Even the trade with English colonies (partly still in the hands of the royalists, as the English Civil War was in its final stages and the Commonwealth of England had not yet imposed its authority throughout the English colonies) was by Dutch merchants. English direct trade was crowded out by a sudden influx of commodities from the Levant, Mediterranean and the Spanish and Portuguese empires, and the West Indies via the Dutch Entrepôt, carried in Dutch ships and for Dutch account.