Mack P. Holt
Henry IV’s young heir, Louis, was only nine years old at his father’s death, so his mother, Marie de Medici, governed as regent until Louis reached his age of majority in 1614 as King Louis XIII. The peace was maintained, however, until the early 1620s when two ambitious Protestant brothers, the duke of Rohan and the duke of Soubise, mounted a military campaign to overthrow the Edict of Nantes. King Louis XIII led military campaigns to defeat them in 1620, 1621, and 1622 in the south of France. Cardinal Richelieu, appointed to the royal council in 1624, urged the king to remove the last Huguenot stronghold, the city of La Rochelle. La Rochelle fell finally in 1628 after a long siege, and a peace treaty was signed in 1629 ending the last war of religion.