He was one of the pettiest and poorest gentlemen of France: he was well-made, but very swarthy, with Spanish features, had a charming voice, played the guitar and lute very well, and was skilled in the arts of gallantry.

By these talents he had succeeded, in finding favour with Madame de Beauvais, much regarded at the Court as having been the King's first mistress.

I have seen her--old, blear-eyed, and half blind,--at the toilette of the Dauphiness of Bavaria, where everybody courted her, because she was still much considered by the King.
Under this protection La Vauguyon succeeded well; was several times sent as ambassador to foreign countries; was made councillor of state, and to the scandal of everybody, was raised to the Order in 1688.

Of late years, having no appointments, he had scarcely the means of living, and endeavoured, but without success, to improve his condition.
Poverty by degrees turned his brain; but a long time passed before it was perceived.

The first proof that he gave of it was at the house of Madame Pelot, widow of the Chief President of the Rouen parliament.