In considering the trade in slaves from Jamaica to the Spanish colonies it is well to keep in mind that this island lay far to the west of all other English possessions in the West Indies. It was located in the very midst of the Spanish possessions from which it had been wrested in 1655 by the expedition of Sir William Penn and Admiral Venables. The people of the island realized their isolation and occasionally attempted to break down the decrees of the Spanish government, which forbade its colonies to have any intercourse with foreigners. Although the English government began a somewhat similar policy with respect to its colonies in the Navigation Act of 1660, it was generally agreed that some exception should be made for the island of Jamaica in connection with the Spanish trade. When Lord Windsor became governor of Jamaica in 1662 he was instructed to endeavor to secure a free commerce with the Spanish colonies. If the governors of the Spanish colonies refused to grant this trade voluntarily, Lord Windsor and the council of the island were given permission to compel the Spanish authorities to acquiesce by the use of force or any other means at their disposal.[71] Accordingly a letter embodying this request was written to the governors of Porto Rico and Santo Domingo, but unfavorable replies were received. In accordance with the king's instructions the Jamaica council determined to obtain a trade by force.[72] This was done by issuing letters of marque to privateers for the purpose of preying upon Spanish ships.[73] In the following year, 1663, as has already been mentioned, Charles II commanded the governors of Barbadoes and Jamaica to permit the Spaniards to buy goods and Negroes in their respective islands, and to refrain from charging duties on these Negroes in case they were reexported by the agents of the Royal Adventurers.[74] This was followed by a royal order of April 29, 1663, commanding the governor to stop all hostile measures against the Spaniards. Sir Charles Lyttleton, the deputy governor, replied that he hoped the attempt to begin a trade with the Spaniards would be successful, especially in Negroes, which the Spaniards could not obtain more easily than in Jamaica.[75]