He died in 1870 of a pulmonary congestion in his hotel on rue Saint-Dominique in Paris. Dying without legitimate issue, his title of Prince of San Donato passed to his nephew Pavel Pavlovitch Demidov.
Cimetière du Père Lachaise. Plot # Family Mausoleum
Il est marié avec Mathilde Laetitia Wilhelmine Bonaparte.
Ils se sont mariés le 1 novembre 1840 à Florence, Firenze, Toscana, Italy, il avait 27 ans.Source 2