Spared during the St Bartholomew’s Day Massacre on 24 August 1572 by virtue of his status as a Prince of the Blood, Henry was nevertheless compelled to abjure Protestantism.
Held virtually captive at the French court for three years, he eventually succeeded in escaping, returned to his own territories, and openly embraced the Protestant faith once more.
In 1580, during the Seventh War of Religion, Henry assumed leadership of the Protestant party. He captured the town of Cahors, whose inhabitants he deliberately spared.
In 1584, the death of the Duke of Alençon, the younger brother of King Henry III, made Henry the legitimate heir to the throne of France.