When the Royal Company learned that the trade in Negroes to the Spanish colonies offered many possibilities it was very much interested. A petition was immediately submitted to the king requesting that, if the Spaniards were allowed to come to Barbadoes for slaves, the whole trade be conferred on the Royal Company. The company declared that the planters in the colonies had no reason to object to this arrangement because they had not engaged in this trade, and moreover an opportunity was being offered to them to become members of the company.[65] The Privy Council was favorable to the company's proposition, and on March 13, 1663, the king instructed Lord Willoughby to permit the Spaniards to trade at Barbadoes for slaves notwithstanding any letters of marque that had been issued against them, or any provisions of the Navigation Act. He declared that the Spaniards were to be allowed to import into Barbadoes only the products of their own colonies, and were not to be permitted to carry away the produce of the English colonies. The effect of this provision was that in addition to slaves the Spaniards might obtain any products imported into Barbadoes from England.[66] The king settled the question of duties on slaves by ordering that ten pieces of eight on each Negro should be paid by all persons who exported slaves from Barbadoes or Jamaica to the Spanish colonies, except the agents of the Royal Company. The company was to pay no export duties on Negroes especially when the Spaniards had made previous contracts for them in England.[67] Probably on account of the export duty on slaves which Willoughby had levied in 1662, the Spaniards were not anxious to return to Barbadoes. The company's factors therefore sent one of their ships with slaves to Terra Firma in order to convince the Spaniards that their desire for a Negro trade was genuine. On this occasion Lord Willoughby and the council of the island exacted L320 in customs from the factors. When the company heard of this procedure it immediately asked the king to enforce the order allowing it to export Negroes free of duty.[68] Thereupon the king ordered Willoughby to make immediate restitution of the L320 and to give the company's factors as much encouragement as possible.[69] Willoughby finally obeyed in a sullen manner. On May 20, 1665 he declared that the company had finally monopolized the Spanish trade for Negroes and that, because the king refused to permit an export duty to be levied on them, there was no revenue from that source.[70] The king's concessions to the Royal Company were of little avail, however, because the Anglo-Dutch war effectually stopped most of the company's trade in Negroes including that from Barbadoes to the Spanish colonies.