He bought depreciated rentes and had them raised to their nominal value by the treasury; he extorted gifts from the financiers for his protection, being Fouquet's confidant in many operations of which he shared the profits.

He was involved in the trial of Fouquet, and in April 1663 was condemned to death for peculation and embezzlement of public funds; but escaping, was executed in effigy.

Having returned secretly to France, he entered the service of Condé, who, unable to meet his creditors, had need of a clever manager to put his affairs in order.

From 1696 he fell ill and withdrew to his estate, where he dictated to his secretary, in four months and a half, his Mémoires, an important source for the history of his time.

In spite of several errors, introduced purposely, they give a clear idea of the life and morals of a financier of the age of Fouquet, and throw light on certain points of the diplomatic history.