During the French Wars at the end of the 18th century, Admiralty policy was to blockade enemy ports and thereby contain all their shipping. Thus, when the Netherlands entered the war as France's ally, Admiral Duncan mounted a blockade of the Dutch fleet in the Texel throughout the summer of 1797. Early in October, taking advantage of Duncan's absence to refit at Yarmouth, the Dutch fleet brock out into the North Sea. Duncan, alerted to the situation by a fast frigate, hastened back to his quarry, engaged the Dutch off Camperdown on 11 October and decisively defeated them in a ferocious action lasting 3½ hours.