Why did the Holy League oppose Henry IV’s claim to the French throne?

The Holy League, an association of Roman Catholics formed during the French Wars of Religion, primarily opposed Henry IV because he was a Protestant leader. When Henry of Navarre became the heir to the French throne in 1584, the League sought to exclude him from the succession to defend the Catholic religion.1

Beyond religious motivations, the League was driven by political objectives, including a desire to limit the power of the monarchy. Supported by Spain, the League established an alternative candidate to the throne and controlled much of France, forcing the king to proscribe the Protestant religion to appease them.1

The opposition to Henry IV persisted even after he became king, as his Protestant faith provided a legitimate pretext for resistance. The conflict only began to wane after Henry IV converted to Roman Catholicism in July 1593, which removed the primary justification for the League's rebellion and led to the gradual submission of major French cities.12