We know how, under the influence of Louvois, the able and insinuating policy directed first by Mazarin, then by Lionne, gave way to a military diplomacy, blunt and aggressive. Louis XIV. was master of Pignerol, acquired in 1632. He was induced by Louvois to cast covetous glances at Casal. In possession of these two places, the French armies could not but dominate Upper Italy, and hold the court of Turin directly at their mercy. The throne of Mantua was then occupied by a young duke, Charles IV. of Gonzago, frivolous, happy-go-lucky, dissipating his wealth at Venice in fêtes and pleasures. In 1677 he had pledged to the Jews the crown revenues for several years. Charles IV. was also Marquis of Montferrat, of which Casal was the capital. Noting with watchful eye the frivolity and financial straits of the young prince, the court of Versailles conceived the bold scheme of buying Casal for hard cash. At this date, one of the principal personages in Mantua was Count Hercules Antony Mattioli. He was born at Bologna on December 1, 1640, of a distinguished family. A brilliant student, he had barely passed his twentieth year when he was elected a professor at the University of Bologna. Afterwards he established himself at Mantua, where Charles III., whose confidence he had won, made him his secretary of state. Charles IV., continuing the favour of his father, not only maintained Mattioli in his office as minister of state, but appointed him an honorary senator, a dignity which was enhanced by the title of Count. Louis XIV. was employing at the capital of the Venetian republic a keen-witted and enterprising ambassador, the Abbé d'Estrades. He saw through the ambitious and intriguing nature of Mattioli, and, towards the end of 1677, succeeded in winning over his support for the designs of the French court on Casal. On January 12, 1678, Louis XIV. with his own hand wrote expressing his thanks to Mattioli, who by-and-by came to Paris. On December 8, the contract was signed, the Duke of Mantua receiving in exchange for Casal 100,000 crowns. In a private audience, Louis XIV. presented Mattioli with a costly diamond and paid him the sum of a hundred double louis.