After Henry III was assassinated on 31 July 1589, Navarre claimed the throne as the first Bourbon king of France, Henry IV. Much of Catholic France, organized into the Catholic League, refused to recognize a Protestant monarch and instead recognized Henry IV's uncle, Charles, Cardinal de Bourbon, as rightful king, and the civil war continued. Henry won a crucial victory at Ivry on 14 March 1590 and, following the death of the Cardinal the same year, the forces of the League lacked an obvious Catholic candidate for the throne and divided into various factions. Nevertheless, as a Protestant, Henry IV was unable to take Paris, a Catholic stronghold, or to decisively defeat his enemies, now supported by the Spanish. He reconverted to Catholicism in 1593—he is said to have remarked, "Paris is well worth a mass"—and was crowned king retroactively to 1589 at the Cathedral of Chartres on 27 February 1594. Early Bourbons in France Henry granted the Edict of Nantes on 13 April 1598, establishing Catholicism as an official state religion but also granting the Huguenots a measure of religious tolerance and political freedom short of full equality with the practice of Catholicism. This compromise ended the religious wars in France. That same year the Treaty of Vervins ended the war with Spain, adjusted the Spanish-French border, and resulted in a belated recognition by Spain of Henry as king of France. Ably assisted by Maximilien de Béthune, duc de Sully, Henry reduced the land tax known as the taille; promoted agriculture, public works, construction of highways, and the first French canal; started such important industries as the tapestry works of the Gobelins; and intervened in favor of Protestants in the duchies and earldoms along the German frontier. This last was to be the cause of his assassination. Henry's marriage to Margaret, which had produced no heir, was annulled in 1599 and he married Marie de Medici, niece of the grand duke of Tuscany. A son, Louis, was born to them in 1601. Henry IV was assassinated on 14 May 1610 in Paris. Louis XIII was only nine years old when he succeeded his father. He was to prove a weak ruler; his reign was effectively a series of distinct regimes, depending who held the effective reins of power. At first, Marie de Medici, his mother, served as regent and advanced a pro-Spanish policy. To deal with the financial troubles