The sanctuary at Mandeure seems presently to be one of the major civic sanctuaries in the territory of the Sequani and one of the largest in eastern Gaul and Germania. Consecrated to Mars, probably accompanied by consort divinities and deified emperors, it is built within an enclosure with numerous buildings. From the Augustan period to the Severan time, extensive building contributions were undertaken. Recent investigations of various buildings (theatre, precinct wall, monumental entrance, secondary temple, culinae, etc.) provide particularly interesting evidence for the study of the evolution of his sacred site in the last decades of its occupation. Besides, the excavation of the castrum gives important data about the rate and modalities of the reuse of the monumental equipment; its wall precinct was composed of spolia from the large public constructions. During a certain amount of time some monuments such as the theater seem to be spared whereas others are completely dismantled. Moreover, the edification of a church at the end of the 4th c. leads to a reassessment of the history of the Mars sanctuary in the last decades and the early periode of Christianization. It is difficult to consider with certainty the relations between complex events such as the abandonment of the some parts of the sanctuary in the 3rd c., the dismantling of other ones from the mid 4th c. and the construction of a Christian cult place at the end of that century. For the time being we shall carefully avoid providing a synthesis on the occupation of the sanctuary betwen 3rd c. and 5th c., but thoughts will be based on observations collected from the recent excavations in the sanctuary and the castrum.