Charles IX began his reign with Catherine serving as a dominant force in royal affairs.
Charles IX formally began his reign on December 5, 1560, ushering in a regency dominated by his mother, Catherine de' Medici. As regent, she capitalized on her political acumen to stabilize the kingdom amid rising religious conflicts. Her role extended beyond typical regency duties, involving direct involvement in government decisions, which reflected her effective power as a ruler and administrator during a climate of intense sectarian strife.