In the 16th century, England and the Netherlands had been close allies against the ambitions of the Habsburgs. They cooperated in fighting the Spanish Armada and England supported the Dutch in the early part of the Eighty Years' War by sending money and troops and maintaining a permanent English representative to the Dutch government to ensure coordination of the joint war effort. The separate peace in 1604 between England and Spain strained this relationship, although an Anglo-Dutch treaty of 1625, due to remain in force until 1640 was the basis of officially cordial relations between the two countries, and also formed the basis of Charles I's Dutch policy. The weakening of Spanish power at the end of the Thirty Years' War in 1648 also meant that many colonial possessions of the Portuguese and some of the Spanish empire and their mineral resources were effectively open to conquest by a stronger power. The ensuing rush for empire brought the former allies into conflict, and the Dutch, having made peace with Spain, quickly replaced the English as dominant traders with the Iberian peninsula, adding to an English resentment about Dutch trade that had steadily grown since 1590. Although the Dutch wished to renew the 1625 treaty, their attempt to do so in 1639 was not responded to, so the treaty lapsed.