Overtures had been made to him, as early as 1807, to enter the Russian service, but Napoleon, hearing of his intention to leave the French army, compelled him to remain in the service with the rank of general of brigade.
Pendekatan telah dilakukan sejak 1807, untuk memasuki tentara Rusia, tetapi Napoleon, mendengar niatnya untuk meninggalkan pasukan Prancis, memaksanya untuk tetap berada di tentara Prancis dengan pangkat Jenderal.