Catherine never forgave Henry III of France (who kept taunting her as "la maîtresse de Saint Megrin") for his part in the assassination of her husband.

At the conclusion of the War of the Three Henrys, she was mindful of the interests of her large family and supported her son Charles as a candidate for the French throne.

[3] The Guises continued to support the queen throughout the regency, and Catherine followed Marie into exile in Blois after Louis XIII assumed the reins of government in 1619.

After returning to the Louvre, the Dowager Duchess - anxious to promote the interests of the House of Guise - resumed plotting against Cardinal Richelieu.

The death of her youngest daughter, the princesse de Conti (who had been implicated in the Day of the Dupes conspiracy), proved a blow to her spirits.