To return, therefore, to the troubles in Hungary, which gave occasion for French intrigue and for the interference of the Porte. The Turks, reinvigorated by the policy of the late Vizier Kiuprili, but directed no longer by his cool experience and judgment, were now not slow to take advantage of the difficulties of Austria. After their defeat at the hands of Montecuculi at St. Gotthard in 1664, they had consented to a twenty years' truce, by which they were still left in possession of the greater part of Hungary, and of that part where the pure Magyar population most prevailed. This truce had not expired when the oppressions exercised in the part of their country remaining to the Emperor drove the Hungarians to arms, and Count Tekeli to seek aid from the Sultan. Ordinarily scrupulous in the observance of their treaty obligations, the Turks were on this occasion overcome by the temptations held out to them of an easy extension of their frontier and of their influence. With the active aid of the Hungarians, and with the tacit consent of France, they deemed it possible to deal a mortal blow at the house of Austria. The Sultan, Mahomet IV., was perhaps not over ambitious, but he was spurred on by the zeal of a servant. The Grand Vizier, Kara Mustapha, though a nephew of the great minister Kiuprili, owed his advancement more to the beauty of his person and to the favour of the Sultana Validé, or Queen Mother, who ruled the ruler of Islam, than to other connexions or to ability. His ambition, however, was believed to aim at no less than a dependent kingdom for himself in Hungary or at Vienna. Here, at all events, and not against the Poles or Russians, did Kara Mustapha determine to gather his laurels and his booty. He had, indeed, already essayed a Russian campaign with little profit. A more striking success and greater glories, more abundant plunder with fewer toils, seemed to be promised by a campaign in the valley of the Danube, than by one among the marshes and forests of Poland, or of the Ukraine.