In spite of the "American Treaty" which had for the moment bound Great Britain and Spain together for mutual protection against the pirates, the designs of land-hungry British courtiers and adventurers were by no means abandoned. Spain was not blind to the fact that she had all powers against her, that were playing an important part in the development of the New World. French, Dutch and British were stung with the desire to appropriate to themselves some of its wealth. For many years the British government had jealously watched the progress of Dutch navigation and commerce. Its settlements in North America had whetted the appetite for colonial expansion, which, once awakened, was bound to be satisfied by whatever means diplomacy or strategy offered. Though England and Spain were then nominally at peace, Cromwell was haunted by dreams of British world power and as soon as the Revolution gave him authority to act as Lord Protector of the Commonwealth, pursued his visions of conquest. The act of navigation which was issued in the year 1651 does not with a word mention British monopoly of the colonies; it only established the principle of exclusive maritime commerce by British vessels, equipped for the most part with British citizens, and prohibited foreigners from importing into the Commonwealth other products than those of her own soil or those the sale of which was established in the importing country. Cromwell's idea was without doubt to attack Dutch commerce and build upon its ruins a national British commerce. Holland opposed in vain the act intended to break the friendly relations between the two nations. Parliament was concerned only about British interests and refused to revoke her laws to please her neighbor and ally. The war between England and Holland became inevitable. Cromwell's squadron triumphed and Dutch commerce had to give way to British. This lesson was not lost upon France which was also haunted by visions of colonial empire and was therefore interested in defending the principle of monopoly. As early as the reign of Queen Isabella, French ambition and desire for colonial possessions had become manifest. As British vessels began to prey upon Spanish colonies, France followed their operations with keen interest and at opportune moments managed to acquire a slice of territory in the New World. In the year when the British had taken possession of Barbadoes, France took half of San Cristobal; when the British settled on the other half of that island, the French took possession of Martinique, Guadeloupe and other small islands. They founded a colony in Cayenne and assisted by corsairs got a hold on the western part of Santo Domingo.