His reign will further exacerbate the civil division. Their real policy making alternating periods of prohibition and permission of the Protestant religion exacerbates passions. And as if that were not enough to complete the picture, in 1584, Henry of Navarre, head of the Protestants, became the legitimate successor to the throne. "The kingdom, economically exsangue down to political chaos. The monarchy crashes into the Catholic League of Guise and meet with the so-called Day of the Barricades, in May 1588, its most serious crisis before the revolution of 1789" .
This time is Henri de Guise, who obsessed with her victories, dreams of overthrowing the king, who should in fact camouflaged escape the Louvre. Revenge of the King not long in coming: Dec. 23, when the call of the Estates General at Blois, the monarch invites the Duke of Guise and does kill by his own bodyguard. The next day murders his brother the Cardinal of Guise. Paris immediately counsel of the sixteen pronounce the fall of the king and appointed the Duke of Mayenne (other Guise!) Lieutenant General of the kingdom. In the following year, encouraged by the Pope himself to go to Rome to apologize for the crime, Henri III decides to ally himself nothing less and nothing more than his old enemy Henry of Navarre, and together they undertake the siege of Paris. It is precisely here, in Saint-Cloud, on August 2, 1589, a Dominican monk named Jacques Clement stabbed to death the king of France. The first thing to do Henri IV, during his first five-year reign, is to conquer his kingdom.