t in the southern Netherlands. He saw
that France was a waxing, Spain a waning power, and he had no desire to
see France in possession of territory bordering on the United Provinces.
This feeling on his part was possibly the cause of the somewhat
dilatory character of his military operations in 1641 and 1642. The
revolt of Portugal from Spain in December, 1640, had at first been
welcomed by the Dutch, but not for long. The great and successful
operations of the East and West India Companies had been chiefly carried
on at the expense of the Portuguese, not of the Spaniards. The great
obstacle to peace with Spain had been the concession of the right to
trade in the Indies. It was Portugal, rather than Spain, which now stood
in the way of the Dutch merchants obtaining that right, for the Spanish
government, in its eagerness to stamp out a rebellion which had spread
from the Peninsula to all the Portuguese colonies, was quite ready to
sacrifice these to secure Dutch neutrality in Europe. The dazzling
victory of the French under the young Duke of Enghien over a veteran
Spanish army at Rocroi (May, 1643) also had its effect upon the mind of
the prince. With prophetic foresight, he rightly dreaded a France too
decisively victorious. In the negotiations for a general peace between
all the contending powers in the Thirty Years' War, which dragged on
their slow length from 1643 to 1648, the stadholder became more and
more convinced that it was in the interest of the Dutch to maintain
Spain as a counterpoise to the growing power of France, and to secure
the favourable terms, which, in her extremity, Spain would be ready to
offer.

At first, however, there was no breach in the close relations with
France; and Frederick Henry, though hampered by ill-health, showed in
his last campaigns all his old skill in siege-craft. By the successive
captures of Hertogenbosch, Maestricht and Breda he had secured the
frontiers of the republic in the south and south-east. He now turned to
the north-west corner of Flanders. In 1644 he took the strongly
fortified post of Sas-van-Gent, situated on the Ley, the canalised river
connecting Ghent with the Scheldt. In 1645 he laid siege to and captured
the town of Hulst, and thus gained complete possession of the strip of
territory south of the Scheldt, known as the Land of Waes, which had
been protected by these two strongholds, and which has since been called
Dutch Flanders.

Very shortly after the cap