War was accordingly declared in May 1672, and the naval force of England was employed in meeting that of the Dutch by sea; while Louis led a powerful army across the Rhine, and in a very short time had nearly reduced the whole of the Seven Provinces. In this emergency the Dutch could only save themselves from absolute ruin by laying a great part of their country under water. The English, who had not entered heartily into this war, soon began to be alarmed for the fate of Holland, which was almost their only support against the dread of Popery; and though forbidden under severe penalties to censure the government measures, they soon contrived to exhibit so much dissatisfaction, as to render a change of policy unavoidable.
The king found it necessary to assemble his Parliament (February 1673), and it was no sooner met than it passed some acts highly unfavorable to his designs. Among these was the famous Test Act, so called because it enacted the imposition of a religious oath upon all persons about to enter the public service, the design being to exclude the Catholics from office. Above all things, the House of Commons declared that it would grant no more supplies for the Dutch war. The king resolved to prorogue the assembly; but before he could do so, they voted the alliance with France, and several of his ministers to be _grievances_. Charles, who, in wishing to be absolute, had been inspired by no other motive than a desire of ease, now saw that there was a better chance of his favorite indulgence in giving way to his subjects than in any other course; and he at once abandoned all his former measures, and concluded a separate peace with Holland. This country was now beginning, under the conduct of the Prince of Orange, to make a good defense against the French, which it was the better enabled to do by obtaining the friendship of Germany and Spain. In the year 1678, after a war which, without any decisive victories, will ever reflect lustre upon Holland, a peace was concluded. The Prince of Orange, in the previous year, had married the Princess Mary, the eldest daughter of the Duke of York, and educated in the reformed faith――an alliance which pleased the English, from its strengthening the Protestant interest, and which was destined, some years after, to bring about important results.