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 of France, Louis summoned the Estates General in 1614; this would be the last time that body met until the eve of the French Revolution. Marie arranged the 1615 marriage of Louis to Anne of Austria, the daughter of King Philip III of Spain.