Mary de Medici forsook the man she had raised to some degree of eminence, and declared that he had shown himself ungrateful. The nobility in general felt his power tyrannical, and the clergy thought that he sacrificed the Church to the interests of the State in politics. Louis XIII was restive sometimes under the heavy hand of the Cardinal, who dared to point out the royal weaknesses and to insist that he should try to overcome them.
Richelieu was very skilful in avoiding the pitfalls that beset his path as statesman. He had many spies in his service, paid to bring him reports of his enemies' speech and actions. Great ladies of the court did not disdain to betray their friends, and priests even advised penitents in the Confessional to act as the Cardinal wished them. When any treachery was discovered, it was punished swiftly. The Cardinal refused to spare men of the highest rank who plotted against the King or his ministers, for he had seen the dangers of revolt and decided to stamp it out relentlessly. Some strain of chivalry forbade him to treat women with the same severity he showed to male conspirators. He had a cunning adversary in one Madame de Chevreuse, who would ride with the fearless speed of a man to outwit any scheme of Richelieu.
An Application to the Cardinal for his Favour (Walter Gay)
The life of a king in feeble health was all that stood between the Cardinal and ruin, and several times it seemed impossible that he should outwit his enemies. Louis XIII fell ill in 1630. At the end of September he was not expected to survive, and the physicians bade him attend to his soul's welfare.
The Cardinal's enemies exulted, openly declaring that the King's adviser should die with the King. The heir to the throne was Louis' brother Gaston, a weak and cowardly prince, who detested the minister in office and hoped to overthrow him. When the sufferer recovered there was much disappointment to be concealed. The Queen-Mother had set her heart on Marillac being made head of the army in Richelieu's place, and had secret designs to make Marillac's brother, then the guard of the seals, the chief minister.
Louis was induced to say that he would dismiss the Cardinal when he was completely recovered from his illness, but he did not feel himself bound by the promise when he had rid himself of Marie de Medici and felt once again the influence of Richelieu. He went to Versailles to hunt on November 11th, 1630, and there met the Cardinal, who was able to convince him that it would be best for the interests of France to have a strong and dauntless minister dominating all the petty offices in the State instead of a number of incapable, greedy intriguers such as would be appointed by Marie de Medici. On this Day of Dupes the court was over-confident of success, believing that the Cardinal had fled from the disgrace that would shortly overtake him. The joy of the courtiers was banished by a message that Marillac was to be dismissed. The Queen-Mother knew at once that her schemes had failed, and that her son had extricated himself from her toils that he might retain Richelieu.
Marshal Marillac and his brother were both condemned to death. Another noble, Bassompierre, was arrested and put in the Bastille because he was known to have sympathized with the Cardinal's enemies. Richelieu did not rid himself so easily of Marie de Medici, who was his deadliest enemy. She went into banishment voluntarily, but continued to devise many plots with the Spanish enemies of France, for she had no scruples in availing herself of foreign help against the hated minister.