He availed himself of the reviving interest in legitimism and Catholicism which was represented by Bonald and Joseph de Maistre, of the nature worship of Rousseau and Bernardin de Saint Pierre, of the sentimentalism of Madame de Stael, of the medievalism and the romance of Chateaubriand and Scott, of the maladie du siecle of Chateaubriand and Byron.
Having been appointed assistant lecturer and afterwards full lecturer at the Ecole des Hautes Etudes, it was to the town of St Omer that he devoted his first lectures and his first important work, Histoire de la vile de Saint-Omer et de ses institutions jusqu'au XI V e siecle (1877).
Examples of his attempted historical writing are Histoire du siecle d'Alexandre le Grand (Amsterdam, 1762), and Histoire impartiale des Jesuites (Madrid, 1768), the latter condemned to be burned.
See La Fondation de la regence d'Alger, histoire des Barberousse, chronique arabe du X VI siecle published by Sander Rang and Ferdinand Denis, Paris, 1837 - for a curious Moslem version of their story.
The 11th century only has been treated in detail by Louis Halphen, in Le Comte d'Anjou au XP siecle (Paris, 1906), which has a preface with bibliography and an introduction dealing with the history of Anjou in the 10th century.