To the monastery of St Omer, and shut up his young son Thierry in that of St Wandrille.
On the top of a hill are the ruins of a castle, which is said to have been built by Charles Martel for the Frankish king, Thierry IV., and is plainly the origin of the name of the town.
Guillaume, son of Thierry or Theodoric and of Alde, daughter of Charles Martel, was born in the north of France about the middle of the 8th century.
In 1817 he began in a treatise entitled L'Industrie to propound his socialistic views, which he further developed in L'Organisateur (181q), a periodical on which Augustin Thierry and Auguste Comte collaborated.
He, however, soon realized that the charters of one town can only be understood by comparing them with those of other towns, and he was gradually led to continue the work which Augustin Thierry had broadly outlined in his studies on the Tiers Etat.
D'Arbois de Jubainville, Deux Manieres d'ecrire l'histoire: critique de Bossuet, d'Augustin Thierry et de Fustel de Coulanges (1896); and Gabriel Monod, Portraits et souvenirs (1897).