Richelieu reduced the power of the nobles by relentless {122} measures that struck at their feudal independence. No fortresses were to be held by them unless they lived on the frontiers of France, where some defence was necessary against a foreign enemy. When their strong castles were pulled down, the great lords seemed to have lost much of their ancient dignity. They were forbidden to duel, and dared not disobey the law after they had seen the guilty brought relentlessly to the scaffold. The first families of France had to acknowledge a superior in the mighty Cardinal Richelieu. Intendants were sent out to govern provinces and diminish the local influence of the landlords. Most of these were men of inferior rank to the nobility, who found themselves compelled to go to the wars if they wished to earn distinction. The result was good, for it added many recruits to the land and sea forces. In 1629, the Cardinal donned sword and cuirass and led out the royal army to the support of the Duke of Mantua, a French nobleman who had inherited an Italian duchy and found his rights disputed by both Spain and Savoy. Louis XIII accompanied Richelieu and showed himself a brave soldier. Their road to Italy was by the Pass of Susa, thick with snow in the early spring and dangerous from the presence of Savoy's hostile troups. They forced their way into Italy, and there Richelieu remained to make terms with the enemy, while Louis returned to his kingdom. Richelieu induced both Spain and Savoy to acknowledge the rights of the Duke of Mantua, and then turned his attention to the resistance which had been organized in Southern France by the Protestants under the Duke of Rohan. The latter had obtained promises of aid from Charles I of England and Philip IV of Spain, but found that his allies deserted him at a critical {123} moment and left him to face the formidable army of the Cardinal. The Huguenots submitted to their fate in the summer of 1629, finding themselves in a worse plight than they had been when they surrendered La Rochelle, for Richelieu treated with them no longer as with a foreign power. He expected them to offer him the servile obedience of conquered rebels. Henceforth he exerted himself to restore the full supremacy of the Catholic faith in France by making as many converts as was possible and by opening Jesuit and Capuchin missions in the Protestant places. "Some were brought to see the truth by fear and some by favour." Yet Richelieu did not play the part of a persecutor in the State, for he was afraid of weakening France by driving away heretics who might help to increase her strength in foreign warfare. He was pleased to find so many of the Huguenots loyal to their King, and rejoiced that there would never be the possibility of some discontented nobleman rising against his rule with a Protestant force in the background. The Huguenots devoted their time to peaceful