It was clear that France must intervene at once, if the fruits of the expedition to Susa were not to be lost, and it was decided to send a powerful army into Italy. Louis XIII would have gone in person, but his health was unequal to the trials of another winter campaign, besides which there was trouble with _Monsieur_, who, in the previous September, as the result of differences with the King over the latter’s refusal to permit his marriage with Marie de Gonzaga, daughter of the Duke of Mantua, had retired into Lorraine and had not yet been persuaded to return; while there was also a possibility that the Imperialists might invade Champagne or the Three Bishoprics. The King accordingly decided to entrust the command to Richelieu, with Créquy and Bassompierre as his lieutenant-generals. “But,” says the latter, “M. de Schomberg, who aspired to my charge, caused pressing instances to be made by the ambassadors of Venice and Mantua to send me into Switzerland, for three purposes: the first, to ascertain what means there might be to liberate the Grisons and drive out the Imperial army; the second, to prevent the Imperialists in Italy being reinforced by troops from Switzerland; and the third, to raise powerful levies, if there were need of them. So that the Cardinal told me one morning that it was necessary for me to make a journey into Switzerland, which would not last long, and that my place and my charge would, notwithstanding, be preserved in the Army of Italy. I accepted this commission, since the King desired to charge me with it, and began preparations for my journey, as did the Cardinal likewise for his journey to Italy.” Before his departure Richelieu gave “a superb _fête_ to the King and the Queens, with comedies, ballets, and excellent music.” Then, on December 29, he set out for Lyons, with the proud title of “Lieutenant-General, representing the person of the King in his army within and without the realm.” * * * * *