Henry succeeded to Navarre as Henry III when his mother died in 1572. That same year Catherine de' Medici, mother of King Charles IX of France, arranged for the marriage of her daughter, Margaret of Valois, to Henry, ostensibly to advance peace between Catholics and Huguenots. Many Huguenots gathered in Paris for the wedding on 24 August, but were ambushed and slaughtered by Catholics in the St. Bartholomew's Day Massacre. Henry saved his own life by converting to Catholicism. He repudiated his conversion in 1576 and resumed his leadership of the Huguenots.