[Sidenote: § 6. Strength of France.] The French monarchy was stronger for external enterprise than ever. By crushing all resistance, it had no longer to fear occupation for its energies at home, and by its tolerance of religion it had rendered itself capable of accepting the service of all its subjects, and it could offer its alliance to Protestant states without fear of suffering a rebuff. [Sidenote: § 7. Richelieu and the Imperialists in Italy.] Richelieu was again able to turn his attention to Italy. In the summer of 1629 an imperialist force of 20,000 men descended from the Alps and laid siege to Mantua. Ferdinand, having established peace in Germany, fancied that he could take up again in Italy the work which had been too great for Barbarossa. Spinola came to his aid with an army of equal force, and recommenced the attack upon Casale. In the spring of 1630 Richelieu was once more in Italy. Cardinal as he was, he was placed in command of the army. But instead of marching against the Spaniards, he turned first upon the Duke of Savoy. Seizing Pignerol and Saluces, he gained possession of the Alpine passes. Then, with Piedmont at his feet, he passed on to relieve Casale, and forced the Spanish besiegers to retreat. But Richelieu was prudent as well as daring, and he left Mantua for the present in the hands of Spain and the Emperor. [Sidenote: § 8. State of Germany.] It was a hard thing to attack the united forces of Spain and the Empire face to face. It might be easier to support their enemies abroad, and to favour dissensions at home. In the Netherlands, the Dutch, encouraged by the diversion of the Italian war, were at last taking the offensive, and entering upon that aggressive warfare which ended by bringing the whole of North Brabant under their authority. In the north, Gustavus had concluded a peace with Poland, and was making preparations for actual intervention in Germany. In all this Richelieu was deeply interested. An ambassador of Lewis was engaged in arranging with Gustavus the terms on which France should assist him in the attack upon the Empire which he already contemplated. [Sidenote: § 9. Richelieu's expectations.] Not that even Richelieu foresaw the possibility of the magnificent results which were to follow from that enterprise. In 1630, as in 1624 and 1625, he would have preferred that a Protestant power should not be too successful. He would rather conquer with Sweden than not at all. But he would rather conquer with the help of the League than with the help of Sweden. Gustavus might be pushed on to do his best. He would effect a diversion, and that would be enough. SECTION III.--_Wallenstein deprived of his Command._ [Sidenote: § 1. Strong position of Wallenstein.]