Marie Stuart passed out of French history, and the power of the Guises was at an end.

The fates were certainly fighting on the side of Catharine.
There are hints that the fine Italian hand may be seen in this event which at one stroke removed every obstacle from her path! However this may be, Catharine wasted no regrets upon the death of a son which made her queen regent during the minority of her second son, Charles, now ten years of age (1560).
There was no time to lose.

Her control over the feeble Charles IX.
before he reached his majority must be absolute.

Every impulse toward mercy must be extinguished.
What can be said of a mother who seeks to exterminate every germ of truth or virtue in her son; who immerses him in degrading vices in order to deaden his too sensitive conscience and make him a willing tool for her purposes?
Inheriting the splendid intelligence as well as genius for statecraft of the Medici, nourished from her infancy upon Machiavellian principles, cold and cruel by nature, this Florentine woman has written her name in blood across the pages of French history.
There were two main ends to be kept in view: the destruction of the Guises, and the extermination of the Huguenots, as the Protestants were now called.

These were difficult to reconcile, but both must be accomplished.
Coligny, the splendid old admiral and Huguenot, hero of the nation, he, too, must go.