Henry IV (13 December 1553 – 14 May 1610), Henri-Quatre, also known by the epithet "Good King Henry", was King of Navarre (as Henry III) from 1572 to 1610 and King of France from 1589 to 1610. He was the first French monarch of the House of Bourbon.

Baptised as a Catholic but raised in the Protestant faith by his mother Jeanne d'Albret, Queen of Navarre, he inherited the throne of Navarre in 1572 on the death of his mother. As a Huguenot, Henry was involved in the French Wars of Religion, barely escaping assassination in the St. Bartholomew's Day massacre, and later led Protestant forces against the royal army. Henry, as Head of the House of Bourbon, was a direct male-line descendant of Louis IX of France, and "first prince of the blood". Upon the death of his brother-in-law and distant cousin Henry III of France in 1589, Henry was called to the French succession by the Salic law. He initially kept the Protestant faith and had to fight against the Catholic League, which denied that he could wear France's crown as a Protestant, to obtain mastery over his kingdom.

After four years of stalemate, he found it prudent to abjure the Calvinist faith. As a pragmatic politician (in the parlance of the time, a politique), he displayed an unusual religious tolerance for the era. Notably, he promulgated the Edict of Nantes in 1598, which guaranteed religious liberties to Protestants, thereby effectively ending the Wars of Religion. He was assassinated by François Ravaillac, a fanatical Catholic, and was succeeded by his son Louis XIII.