Once again it was necessary to send a special envoy to London. The chosen ambassador this time was Jacob Cats, better known as the People's Poet of the Netherlands than as a statesman, though he was far from being undistinguished in the latter capacity, seeing that he was to fill for a number of years the important post of Grand Pensionary of Holland. He departed upon his mission March 9, 1627. His object was to negotiate a Navigation Treaty (_traité de Marine_) dealing with the various thorny questions regarding contraband of war and right of search at sea which had been causing so much trouble. But no sooner had the conferences with the Privy Council begun than the Dutch envoy was confronted with complaints that the old outstanding disputes, the indemnities claimed in reparation for the Amboina massacre, and for the acts of violence committed by the herring fishers off the coast of Scotland, and by the whale fishers at Spitzbergen, had never been settled. Cats had to plead that these matters were not included in his instructions, and after some controversy he succeeded in securing the postponement of these obtrusive and troublesome matters. They were at the first suitable opportunity to be discussed with the resident ambassador, Joachimi, who would be furnished with special instructions from the States. The policy of delay, which had proved so successful in the past, once more gained for the Netherlanders all that they required. The fisheries went on, under protest indeed, but undisturbed. The indemnities continued to be claimed, but remained unpaid. The main purpose of Cats's mission was, however, not achieved. No agreement about contraband and right of search and seizure was reached. The comment of Aitzema upon the negotiations is worth reproducing; it is scarcely possible to describe what took place more pithily or with greater acuteness:
'With these and such-like proposals, with plaints and counterplaints, was the time spent, without either the one or the other being made any the wiser. Each one thinks that he is most in the right; everybody looks outwards, nobody homewards, and for much of the time each was taxing the other with offences in which they themselves were the more guilty. The big fishes eat the small ones. He who has the might uses it; every one speaks merely of uprightness, of sincerity, of affection, and there is nothing but deception and hypocrisy on all sides. The English thought also (as was quite true) that they had done much for the common cause and for the Reformed Religion: and that it behoved this State likewise to suffer some inconvenience in their commerce; because otherwise all business which was in England, would find its way to the United Provinces, if these with too great and undisturbed freedom should use the sea, and not the English. Thus the Ministers of this State did not accomplish much. To Heer Cats, however, an honourable farewell was accorded with the usual present, and the dignity of Knighthood. He returned to the Hague August 30.'