Several encounters now took place, and the Dutch sent out fire-ships by night in the hope of destroying their enemy.  The attempt, however, failed, and in the end the French and English mercenaries in the Dutch service, becoming tired of the struggle, worked their influence in the cause of surrender.  Shortly after this occurred, a powerful fleet of Dutch ships, under Baldwin Henrick, came in sight, but on seeing the Spanish standards flying instead of the Dutch, sailed away to the north.  Had it remained, it would undoubtedly have gained a decisive victory, since the Iberian forces were in much confusion.  The Dutch prisoners were honourably treated, and in the end returned to Holland, where they met with a somewhat contemptuous reception on the part of their fellow-countrymen.

In 1627 the Dutch West India fleet fell in with a Mexican treasure fleet, captured this in its entirety, and the enormous wealth thus gained gave great impetus to the enterprises of this kind.  The Dutch now raided the north of the Continent, and in 1629 prepared an important expedition against Pernambuco.  Fifty vessels sailed from Holland for this purpose.  The force landed under the Dutch commander Wardenburg, and commenced operations in earnest.  First the town of Olinda, and then the neighbouring town of Recife, were captured, after very severe fighting.  It was some while, however, ere the position of the Dutch became secure, and even the short passage between the twin towns could only be effected in circumstances of great danger and difficulty, owing to the raids of the investing Portuguese.

Soon after this the Dutch captured other neighbouring ports, such as Nazareth and Paraiba.  The dominion of Holland in Northern Brazil now appeared assured.  At the same time the counter attacks of the Portuguese were ceaseless, and the leaders of the Dutch garrisons in South America made representations to the Netherlands in favour of reinforcements and a commander of real note.  In response, Prince Mauritz, Count of Nassau, was sent out to take supreme control of the Dutch ventures on Brazilian soil.  A personality more fitted for this particular purpose could scarcely have been lighted upon.  For Prince Mauritz was not only a brave soldier, but a tactful and chivalrous enemy; indeed, his figure stands out in glowing colours in this campaign among the woods of the far southern coast, and the continuance of the Dutch dominion was no doubt largely due to his individuality.  His arrival with nearly 3,000 men inspired the worn soldiers of Holland with new confidence.  Ceara was captured, and Sao Jorge da Mina was attacked and taken as well.