Mont Lassois is a relevant outlier located in the commune of Vix, near Châtillon-sur-Seine in the north of Côte-d'Or. It lays in the upper valley of the Seine for around 100 meters, and a 12th-century church labeled it as a historical monument. Moreover, Mont Lassois has been part of excavations and relevant archaeological discoveries concerning the Hallstatt civilization.
Geography and vegetation
In general Mont Lassois has the shape of a 'J' oriented south–north. The main side, at 306.4 meters from the peak, is known as Mont Saint-Marcel. While the second side, at 280 meters' altitude and oriented east–west, is called Mont Roussillon. Between these two sides there is Saint-Marcel church.
Covered by coppice and forests, Mont Lassois offers in its upper part wide grassy clearings while its lower parts offer cereal and forage crops. Since 1980, wine culture, which was left at the beginning of the 20th century, was re-established on Mont Lassois' slopes: pinot noir and chardonnay grapes for the production of crémant du Châtillonnais.
History
Oppidum of the Celtic period
Mont Lassois covers the course of the Seine and occupied it since the Neolithic. Also, it worked as an oppidum that seems to have controlled the circulation of tin from Great Britain to Italy at the end of the Hallstatt. The Vix Palace and the fortified city that surrounds it bear witness to this period. The local population, ruled by a female aristocracy in the 6th century BC, took advantage of this situation to tax the passing convoys. The resulting opulence is shown through the richness of the burials built according to the funerary rite of the chariot tomb. Among others, a very rich tumulus at Vix contains the remains of a woman, probably a queen or a priestess, a revealing discovery about the status of women in Celtic society. The function of Mont Lassois then seems to change temporarily to the benefit of the development by the Lingones of Vertillum, which are 20 km away.
Late Antiquity and Merovingian period
At the end of the Gallo-Roman period the function of the lower part of the oppidum and the surrounding plain by a vicus would be at the origin of the mountain reconquest and the appearance of the city of Latiscum which raises the Hallstatian walls. According to the late story of a monk of Pothières, at the end of the 4th century, the vandals of Crocus, who devastated the cities of the Rhone valley before being defeated in front of Arles, besieged and destroyed the city of Latiscum which was however quickly rebuilt. Latiscum seems to have been Christianized very early on, as evidenced by shards decorated with Christian motifs from Gallo-Roman workshops in Argonne. Around 451, threatened by the Huns, Saint-Loup, bishop of Troyes, took refuge there, and around 519, Saint-Valentin, founder of the abbey of Griselle, was born there. Latiscum lives on and develops during the Early Middle Ages when it becomes a major city as shown by the Merovingian necropolis, found near the summit, and the Merovingian and Carolingian coins, found bearing the mention of Latiscum.
Carolingian period
During the Carolingian period the settlement moved to Roussillon Mountain, where an oratory was dedicated to Saint Marcel in the 9th century. Latisco appears then under the name of Castellum, a castle in the center of the castrum, a fortified village on a height. In the vulgar language of that time, the word Latisco became Latss. Lassois was then a pagus (a Latin word that means 'country' in English) and an important archdeaconry of the diocese of Langres, which included Bar-sur-Seine and Châtillon, when the Count Palatine Girart de Roussillon, founder of the abbey of Pothières a few kilometers away and of Vézelay, built a castle there. In May 859, a provincial council governed by Rémy, archbishop of Lyon, dismissed him from all his offices, including his fortress of Lassois which was razed to the ground. At that time, Mount Roussillon was home to a small monastery belonging to the abbey of Saint-Marcel-lès-Chalon, which, around 887, ceded it on to Geilon, bishop of Langres.