Located in the Escaut Valley, thirteen kilometers southwest of Cambrai, the Cistercian Abbey of Vaucelles was founded in 1132 by Hugues d’Oisy, lord of Cambrai, under the spiritual direction of Bernard of Clairvaux. A large part of the abbey was destroyed during the Revolution. Monastic buildings remained only the aisle of the monks, which closed the cloister to the east, and the abbey palace of the eighteenth century, which were reconverted. The occupation of the site by the Germans during the Great War ended the embellishment work undertaken by the family Fontana, owner since 1898. The fire marked the end of the conflict: the building of the monks lost its roof and its first floor, while the abbey palace was almost completely destroyed. In 1920, the monks’ building was classified as a historic monument. Beginning a series of works that intensified from the 1970s. Into the hands of the family Lagoutte, restored buildings are opened to the public. A new page is turning in December 2017 since the abbey becomes the tenth cultural equipment of the department of North.This work focuses on two monuments of the twelfth and thirteenth centuries: the building of the monks, the only one that is today largely preserved, and the church dedicated in 1235 which benefited from some archaeological operations between 1879 and 2002 still unpublished. Today the monk’s building benefits from a study of building archaeology confirming a construction from 1170 attributed by the texts to the abbot Aleaume (1166-1181). He chose, forty years after the foundation of the abbey, to build a monumental abbey inspired by Clairvaux, the mother house. This building is a typical example of a monastic typology set up by the Benedictines and specified by the Cistercians during the first half of the twelfth century. It is illustrated by a work of the rational and quality stone and a sober decor in the spirit of the Cistercians.The archaeological analysis of the remains of north transept’, adjoining the monks’ building, encourages the attribution to Aleaume abbot, not only of the construction of the east and south aisles of the cloister, but also the conception of the overall project of a great perennial abbey with a new church. This hypothesis is also based on a new reading of the texts. But as suggested by the study of the remains, the general structure of the church of Aleaume was modified to give it a new monumentality. These works, to which must be added the construction of an imposing choir, are perhaps due to the abbot Godescalc (1181-1198) who disappeared between 1192 and 1194, after the reception by the abbot of Clairvaux of a blame from the General Chapter of the Order for the sumptuousness of the abbey. The excavation carried out in 1988 revealed the remains of a choir presumably posterior to the cross of the transept. The singularity of his plan, with ambulatory and discontinuous radiating chapels, unique within the Cistercian order, brought Villard de Honnecourt to draw it in his notebook around 1210/1215-1225, according to the recent dating proposed by Jean Wirth. Completed in 1216, this choir testifies to gothic architectural practices, that manifested in the region of northern France and in the counties of Champagne, Flanders and Hainaut from the last quarter of the twelfth century and up to the middle from the thirteenth century. The abbot and his master builder found their models outside the order. They were inspired by Benedictine sites like Saint-Benoît-sur-Loire, adapting an old model to new architectural uses.This study, using texts, iconography, archaeology and art history, invites us to take a new look at the Vaucelles abbey, through two major buildings built between 1170 and 1216.