Flanders, Brabant and Hainault were speedily overrun.  This rapid advance towards their borders caused no small consternation in Holland, and De Witt’s efforts to reach an understanding with King Louis proved unavailing.  The States were not in a position to attempt an armed intervention, and the once formidable Spanish power was now feeble and decrepit.  The only hope lay in the formation of a coalition.  De Witt therefore turned to England and Sweden for help.

The anti-French party in Sweden was then predominant; and Dohna, the Swedish ambassador at the Hague, was ordered to go to London, there to further the efforts of the newly appointed Dutch envoy, John Meerman, for the formation of a coalition to check French aggrandisement.  They had difficulties to overcome.  The English were sore at the results of the peace of Breda.  Charles disliked the Dutch and was personally indebted to Louis XIV for many favours.  But the feeling in England was strongly averse to French aggression towards Antwerp.  The fall of Clarendon from power at this time and the accession of Arlington, who was son-in-law to Beverweert, turned the scale in favour of the proposals of De Witt; and Charles found himself obliged to yield.  Sir William Temple, whose residence as English minister at Brussels had convinced him of the gravity of the French menace, was ordered to go to the Hague to confer personally with the council-pensionary and then to proceed to London.  His mission was most promptly and skilfully carried out.  His persuasiveness overcame all obstacles.  After a brief stay in London he returned to the Hague, January 17, 1668.  Even the proverbial slowness of the complicated machinery of the Dutch government did not hinder him from carrying out his mission with almost miraculous rapidity.  Having first secured the full support of De Witt to his proposals, he next, with the aid of the council-pensionary, pressed the urgency of the case upon the States-General with such convincing arguments that the treaty between England and the United Provinces was signed on January 23.  Three days afterwards Dohna was able to announce the adhesion of the Swedish government; and on January 26, the Triple Alliance was an accomplished fact.  It was essentially a defensive alliance, and its main object was to offer mediation between France and Spain in order to moderate the French claims and to back up their mediation, if necessity should arise, by joint action.  As a preliminary precaution, a strong force was promptly placed under the command of Joan Maurice of Nassau, and a fleet of forty-eight ships was fitted out.