The town was divided into two sections and Trosly Breuil. Breuil was a land tax that the mayor of Ebroin gave to the abbey of St. Medard at Soissons in 656. Staffing confirmed in 858 by Charles the Bald.
Trosly, nicknamed Trosly-aux-Bois-le-Trosly Hemp was a royal house in the Carlovingians. Orders are known Carloman visited this place in February 883.
He was held there four councils or general meetings. The first dates back to 909 on June 20, archbishop of Rouen and the Bishop of Cambray took part in the meeting whose decrees divided into fifteen chapters present a sad picture of the situation of the country and the relaxation of ecclesiastical rules. The second council took place in 921 under the chairmanship of the Archbishop of Sens in the presence of King Charles the Simple. It deals with the affairs of the church of Reims.
In 924, the third meeting chaired by Archbishop of Reims Sculphen. Herbert III, Count of Vermandois, there appeared to agree sentenced to return the property he had usurped the bishopric of Cambray. In 927, meeting of the bishops of the province of Reims, where he was question of enlargement of Charles the Simple, the Count of Vermandois kept prisoner.
King Lothaire held in November 956 placitum or a meeting of the estates of the realm. In September 1155, Louis the Younger (1120-1180) freed the king's men in Trosly. In 1258, the land of the lords of Trosly depended Attichy. The Royal Castle was destroyed by the Trosly Norman. It was located near the village between the road to Soissons and the Aisne River.
Breuil was burned in the Jacquerie of 1359. The land belonged to the lords of Guise. The church was burned and besieged the castle. The church was rebuilt in the 16th century.
Happy independent, even rebellious, people in Trosly quickly obtained the right to pasture and the right to use the forest. This right was granted by royal letters in June 1583. It was confirmed by Henri fourth in February 1609 by Louis and Louis the 13th and 14th in 1648.
