Count Mauritz of Nassau had proved himself an able administrator, and it was now the turn of the Dutch to intrigue where before they had fought openly.  In June, 1641, an agreement was negotiated in Europe between Portugal and the United States of the Netherlands, which concluded a truce for ten years.  A year was allowed in order to carry this intelligence to the Dutch commanders in South America and elsewhere.  In order to cement this new friendship, the Dutch further agreed to supply Portugal with arms and ammunition to aid in the common fight against Spain.

The Brazilian policy of Holland was, however, quite different from that proposed in Europe.  Instructions were sent to Count Mauritz of Nassau ordering him to continue in the command, to extend the sphere of the Dutch dominion, and, if possible, to capture Bahia.  These instructions were largely due to the belief held in Holland that Portugal would be unable to maintain her independence for any length of time.

When the news of the truce was first brought to Count Mauritz at Recife, all the outward marks of festivity and great rejoicings were exhibited.  A general fraternization ensued, and the late enemies and temporary friends regaled each other at various banquets.  Thus Paulo da Cunha, the Brazilian patriot, upon whose outlawed head the Count had put a price of 500 florins (to which da Cunha had retorted by placing a price of 2,000 cruzados upon the Count’s), was now invited to feast with Nassau, and the two entered into an intimate and rather chaffing discussion upon the respective prices they had put upon each other’s heads.

Very shortly, however, the Brazilians found reason to suspect the sincerity of the Dutch professions of friendship.  A Dutch fleet sailed north, captured Sao Christovao, and in other places seized a number of Portuguese vessels.  The Portuguese now found themselves in something of a dilemma, owing to the very fact of the independence they had won.  During the Spanish dominion the ports had been manned by the Spaniards as well as by the Portuguese.  This, of course, was no longer the case.  Bahia, for instance, had now lost a great part of its garrison.  The 700 Spaniards and Neapolitans who had served there were honourably treated by the Portuguese, and were sent on their way to Europe, but were captured by the Dutch ere they had left the coast.

The Dutch aggression, as a matter of fact, was not confined to South America.  A Dutch force of 2,000 regular troops had entered Sao Paul de Loanda, the capital of Angola.  The loss of this important Portuguese possession on the west coast of Africa produced a direct effect on South America, for it was from here that the Brazilians had imported all their African slaves.  Thus the whole of this traffic passed entirely into the hands of the Dutch for the time being.  Mauritz of Nassau went the length of suggesting that the territory of Angola should become an appendage of that of Dutch Brazil, as the two were bound so closely by this traffic!  The Dutch had also captured the Island of St. Thomas.  In that place, however, the climate avenged the Portuguese to the full, and the mortality among the Dutch from fever in this island was appalling.