'When Napoleon finally got rid of Moreau, the man who succeeded in general estimation to the vacant and undesirable position of unofficial leader of the unofficial opposition was Jean Baptiste Jules Bernadotte. this man was one of the most despicable and successful trimmers in history. In Moreau's Army of the Rhine he had attained the rank of general of division, but he was in no way a talented leader. Just before Napoleon's return from Egypt he had intrigued to attain the supreme power, but over-reached himself. In Napoleon's coup d'état of the 18th Brumaire he hunted with the hounds and ran with the hare with remarkable success, assuring the Directory on the one hand of his unfaltering support, and yet joining the group of generals who accompanied Napoleon, but characteristically not wearing uniform. In addition, he had a convenient shelter behind a woman's petticoats, for with subtle forethought he had married Joseph Bonaparte's sister-in-law, Desiree Clary. Desiree was a jilted sweetheart of Napoleon's, and what with her hatred of the great man, Joseph's support, and Napoleon's horror of a scandal in the family (combined with a sneaking affection for her) Bernadotte made himself fairly secure all round. But he still continued to intrigue against Napoleon. During the Consulate an extraordinary conspiracy was discovered centering at Rennes, Bernadotte's headquarters. Bernadotte himself was undoubtedly implicated, but he somehow wriggle free from suspicion. To the Republicans he posed as a Republican; the Bourbons were convinced that he was on their side; actually he was working for his own hand, while, thanks to Joseph, he obtained his Marshalate and the principality of Ponte Corvo from the Empire.'

'In action, various unsavorily suspicious incidents occurred in connection with him. In 1806 he took advantage of an ambiduous order to absent his corps both from Jena and Auerstadt; the results of his action might have been far-reaching. Later Benningsen and the Russian army escaped from the trap Napoleon had set for them by capturing vital orders which were on their way to the Prince of Ponte Corvo. At Wagram his corps was routed and broken up.'

-Napoleon and His Court, CS Forester, 81-82.