A fresh anxiety clouded the Pope's pleasures when he heard that France, Spain, Germany, and Switzerland had formed an alliance, and that Francis I. and Charles V. (who succeeded Ferdinand on January 23d) were virtually to divide northern and central Italy between them. This project was abandoned, but in the following year an even more serious event alarmed the Pope. The younger cardinals who had pressed his election were generally aggrieved. Fast and luxurious as most of them were, they had expected a larger pecuniary gratitude on Leo's part, and they observed with annoyance that his relatives and his literary admirers secured the greater part of his lavish gifts. In 1517, one of these worldly young cardinals, Petrucci, conceived a particular animosity against Leo, on account of some injustice done to his brother, and there is little room for doubt that he spoke and thought of having the Pope assassinated. Whether or no we trust the romantic story told by Guicciardini and Giovio, that the surgeon who attended the Pope was to poison his wound, we can hardly accept the opposite rumour, that the whole conspiracy was invented by the Pope or his brother in order to secure money. Petrucci was not offered the option of a fine; and Cardinals Riario and Sauli confessed that they knew of the plot. After a dramatic period of inquiry and incrimination Petrucci was, in spite of the protests of cardinals and ambassadors, strangled in his prison, and the flesh of his guilty servants was torn from their bones with red-hot pincers. Cardinal Riario paid 150,000 ducats for his release, and the less wealthy Cardinal Sauli 25,000. Cardinals Soderini and Castellesi fled, when they were impeached, and their property and that of Cardinal Petrucci was seized.
These events caused the gravest scandal throughout Christendom. Cardinal Riario was the Dean of the Sacred College, and many preferred to think that the plot was an invention for the purpose of securing funds rather than that the cardinals had sunk so low. The dilemma was painful, but we can have little doubt that Leo, at least, was convinced of the reality of the plot. Instead of proceeding with greater caution, however, he went on to give a fresh ground of criticism. In a Consistory which he held on June 26th, he told the cardinals that he was going to add no less than twenty-seven members to their college. Their stormy protests increased his determination, and on July 1st he promoted thirty-one cardinals. The rumour at once spread through Christendom, and is in substance undoubted, that most of the new cardinals paid large sums of money for the dignity; Sanuto makes individual payments rise as high as 30,000 ducats. Some of them were men of low character, and others were either related to, or had lent money to, the Pope.