He was succeeded by his son Louis XIII. (1610-43) who was then a boy of nine years. His mother Mary de' Medici, who acted as regent approved the terms of the Edict of Nantes, but the Huguenots relying on the weakness of the government refused to carry out those portions of the Edict favourable to Catholics, and made demands for greater privileges. They rose in rebellion several times especially in the South, entered into alliance with every rebel noble who took up arms against the king, and acted generally as if they formed a state within a state. Cardinal Richelieu who was for years the actual ruler of France (1624-42),[10] inspired solely by political motives, determined to put an end to a condition of affairs that was highly dangerous to the strength and national unity of the kingdom. He saw that it was impossible for France to extend her power so long as there existed at home a well-organised body of citizens prepared to enter into treasonable relations with foreign enemies, and to turn to their own advantage their country's difficulties. His opportunity came when the Huguenots having concluded an alliance with England rose in rebellion (1627). He laid siege to their strongest fortress, La Rochelle, drove back the fleet which England sent to their assistance, and compelled the city to surrender (1628). By this strong measure he put an end to the power of the Huguenots in France and secured peace and unity for the country, while at the same time he treated the conquered with comparative mildness, confirming the Edict of Nantes (Edict of Nimes, 1629), proclaiming a general amnesty, and restoring the leaders of the rebellion to the property and positions they had forfeited. During the reign of Louis XIV. (1643-1715) the whole tendency of the government was dangerous to the Huguenots. Louis XIV. was determined to make himself absolute ruler of France, and, therefore, he could regard only with the highest disfavour the presence in his territories of a well-organised privileged party like the Huguenots. An opportunity of carrying out his designs came in 1659, when with the approval of the Synod of Montpazier they attempted to negotiate an alliance with England. They were punished with great severity, forbidden to preach in any place without express permission, to attack Catholic doctrines publicly, or to intermarry with Catholics. Converts from Calvinism were encouraged by promises of special concessions. Owing to the disfavour of the king and the energetic action of the clergy and bishops, whose education and culture at that time stood exceedingly high, large numbers of the Huguenots returned to the Church so that in some places, as for example in Normandy, where once they could boast of considerable influence, the sect became almost extinct.