Other than the fact that he didnt have a formal will...? One of the reasons his widow, the rapacious Louise, made such a pitch to Napoleon for the title of 'Prince de Sievres," for which Lannes couldn't be bothered to file the letters patent, and it was also she who insisted the boys, all four of them, receive both titles and revenues. She also tried to be appointed guardian for her sons so she could access the revenues. Naps told her to take a hike, and appointed someone outside the family as guardian.
The lovely Louise paid Naps back when, as dame d'honneur to Marie-Louise, she helped turn the empress away from any inclination to join Naps aftter his abdiction, and offered Wellington her house in Paris as his headquarters.
Quite the *itch, Louise de Montebello.