Instead of concentrating against England, France began another continental war, this time with a new and extraordinary alliance. The Empress of Austria, working on the religious superstitions of the king and upon the anger of the king's mistress, who was piqued at sarcasms uttered against her by Frederick the Great, drew France into an alliance with Austria against Prussia. This alliance was further joined by Russia, Sweden and Poland. The empress urged that the two Roman Catholic powers should unite to take Silesia away from a Protestant king, and expressed her willingness to give to France a part of her possessions in the Netherlands, which France had always desired. Frederick the Great, learning the combination against him, instead of waiting for it to develop, put his armies in motion and invaded Saxony, whose ruler was also King of Poland. This movement, in October, 1756, began the Seven Years' War; which, like the War of the Austrian Succession, but not to the same extent, drew some of the contestants off from the original cause of difference. But while France, having already on hand one large quarrel with her neighbor across the Channel, was thus needlessly entering upon another struggle, with the avowed end of building up that Austrian empire which a wiser policy had long striven to humble, England this time saw clearly where her true interests lay. Making the continental war wholly subsidiary, she turned her efforts upon the sea and the colonies; at the same time supporting Frederick both with money and cordial sympathy in the war for the defence of his kingdom, which so seriously diverted and divided the efforts of France. England thus had really but one war on hand. In the same year the direction of the struggle was taken from the hands of a weak ministry and given into those of the bold and ardent William Pitt, who retained his office till 1761, by which time the ends of the war had practically been secured.