the
Dutch captured Ceylon and Macassar and practically cut off Portuguese
intercourse with the East Indies. At last in August, 1661, a treaty was
signed by which the Dutch abandoned all territorial claims in Brazil,
but were granted freedom of trade and an indemnity of 8,000,000 fl. to
be paid in sixteen years, and, what was more valuable, they retained
possession of their conquests in the East.

The protracted dispute with Portugal was however of quite subordinate
importance to the interest of the Dutch in the complications of the
so-called Northern War. On the abdication of Christina in 1654, Charles
X Gustavus had succeeded to the Swedish throne. The new king was fired
with the ambition of following in the footsteps of Gustavus Adolphus,
and of rendering Sweden supreme in the Baltic by the subjection of
Poland and Denmark. Charles was a man of great force of character and
warlike energy, and he lost no time in attempting to put his schemes of
conquest into execution. Having secured the alliance of the Great
Elector, anxious also to aggrandise himself in Polish Prussia, the
Swedish king declared war against Poland, and in the early summer of
1656 laid siege to Danzig. But the importance of the Baltic trade to
Holland was very great and Danzig was the corn emporium of the Baltic.
Under pressure therefore of the Amsterdam merchants the States-General
despatched (July) a fleet of forty-two ships under Obdam van Wassenaer
through the Sound, which raised the siege of Danzig and with Polish
consent left a garrison in the town. Thus checked, the Swedish king at
Elbing (September, 1656) renewed amicable relations with the republic,
and Danzig was declared a neutral port. At the same time a defensive
alliance was concluded between the States and Denmark. It was obvious
from, this that the Dutch were hostile to Swedish pretensions and
determined to resist them. De Witt was anxious to preserve peace, but
he had against him all the influence of Amsterdam, and that of the able
diplomatist, Van Beuningen, who after being special envoy of the States
at Stockholm had now been sent to Copenhagen. Van Beuningen held that,
whatever the risks of intervention on the part of the States, the
control of the Sound must not fall into the hands of Sweden. The
emergency came sooner than was expected.

Brandenburg having changed sides, the Swedes were expelled from Poland;
and Frederick III of Denmark, despite the advice of De Witt, seized the