 On 2 April the Senate officially deposed Napoleon with the Acte de déchéance de l'Empereur; by 11 April it had approved the Treaty of Fontainebleau and adopted a new constitution to re-establish the Bourbon monarchy.When Napoleon was succeeded by Louis XVIII in April 1814, Talleyrand was one of the key agents of the restoration of the House of Bourbon, although he opposed the new legislation of Louis' rule.Talleyrand was the chief French negotiator at the Congress of Vienna, and, in that same year, he signed the Treaty of Paris.