Louis Philippe would never appear seriously to have entertained the notion of allowing one of his younger sons to accept the crown of Belgium, or of consenting to the union of Belgium with France. Lord Grey had given Talleyrand, who had been directed to sound the British government upon the subject, clearly to understand that the enthronement of a French prince would be regarded as a case for war--a declaration, which, in the words of Sébastiani, "had at least the merit of frankness."[64] Of all the possible candidates for the Belgian crown Louis Philippe justly considered the Duc de Leuchtenberg to be the most undesirable. To have allowed any one connected with the Bonaparte family to become King of Belgium would have been exceedingly dangerous to the French monarchy. "There are no personal objections to him," wrote Sébastiani to Bresson, "but all considerations must give way before the _raison d'état_."[65] The candidate for whose success Louis Philippe was in reality most anxious, and whose selection Sébastiani instructed both Bresson and Talleyrand to advocate cautiously, was Prince Charles of Naples. This young prince was a Neapolitan Bourbon, a brother of the Duchesse de Berri and a nephew of the French queen, Marie Amélie, and Louis Philippe was always as desirous as any king of the old _régime_ to promote the aggrandizement of his family. But when Talleyrand mentioned his name to Lord Grey he was told at once that his connection with the reigning House in France constituted an insuperable objection,[66] whilst from Brussels Bresson reported that "the Prince of Naples had no following."[67]