Maria Theresa was now Empress of Austria, and she succeeded in enlisting the cooeperation of Elizabeth in her unrelenting warfare with Frederic of Prussia. Personal hostility also exasperated Elizabeth against the Prussian monarch, for in some of his writings he had spoken disparagingly of the humble birth of Elizabeth's mother, Catharine, the wife of Peter the First; and a still more unpardonable offense he had committed, when, flushed with wine, at a table where the Russian embassador was present, he had indulged in witticisms in reference to the notorious gallantries of the empress. A woman who could plunge, into the wildest excesses of licentiousness, still had sensibility enough to resent the taunts of the royal philosopher. In 1753, Elizabeth and Maria Theresa entered into an agreement to resist _all further augmentation_ of the Prussian power. In the bloody Seven Years' War between Frederic and Maria Theresa, the heart of Elizabeth was always with the Austrian queen, and for five of those years their armies fought side by side. In the year 1759, Elizabeth sent an army of one hundred thousand men into Prussia. They committed every outrage which fiends could perpetrate; and though victorious over the armies of Frederic, they rendered the country so utterly desolate, that through famine they were compelled to retreat. Burning villages and mangled corpses marked their path. The next year, 1758, another Russian army invaded Prussia, overran nearly the whole kingdom, and captured Konigsburg. The victorious Russians thinking that all of Prussia was to be annexed to their dominions, began to treat the Prussians tenderly and as countrymen. An order was read from the churches, that if any Prussian had cause of complaint against any Russian, he should present it at the military chancery at Konigsburg, where he would infallibly have redress. The inhabitants of the conquered realm were all obliged to swear fealty to the Empress of Russia. The Prussian army was at this time in Silesia, struggling against the troops of Maria Theresa. The warlike Frederic soon returned at the head of his indomitable hosts, and attacking the Russians about six miles from Kustrin, defeated them in one of the most bloody battles on record, and drove the shattered battalions, humiliated and bleeding, out of the territory.