But the Spanish garrison held out obstinately all through the winter and did not surrender until April 26,1636.

The Dutch army had suffered much from exposure and sickness during this long investment and was compelled to abstain for some months from active operations.

Ferdinand thereupon, as soon as he saw that there was no immediate danger of an attack from the north, resolved to avenge himself upon the French for the part they had taken in the preceding year's campaign.

Reinforced by a body of Imperialist troops under Piccolomini he entered France and laid the country waste almost to the gates of Paris.

This bold stroke completely frustrated any plans that the allies may have formed for combined action in the late summer.
The following year the States determined, somewhat against the wishes of Frederick Henry, to send an expedition into Flanders for the capture of Dunkirk.