The Gallo-Roman enclosure of Le Mans, also referred to as the Roman enclosure of Le Mans, is located in the city once known as Vindinum or Vindunum. This city was the capital of the Gallic people, the Aulerci Cenomani. The construction of the enclosure began during the Late Roman Empire. While it was previously believed to date from the end of the 3rd century, recent studies suggest a construction date at the beginning of the 4th century.
The construction work was carried out according to an organized plan and at a considerable cost, which, according to , was indicative of the affluence of the city and its territory. The enclosure retained its military function throughout the Middle Ages and was preserved due to the rise in ground level within the enclosures, which afforded it a supporting role. Following the Middle Ages, the construction of buildings in its immediate vicinity contributed to its longevity.
Originally 1,300 meters long, the enclosure is well-preserved over approximately 500 meters. It features exquisite geometric decorations crafted with the polychrome materials used in its construction. These decorations are unique to the enclosure and are considered to be without equivalent in France, as observed. The vibrant colors of the enclosure earned Le Mans the name "Red City."
The monument has been studied intermittently since the 16th century, with more rigorous scientific investigation beginning in the 19th century. The number of studies increased significantly from the 1980s onwards, driven by local community efforts concerned about its deterioration and potential loss. As a result of the work that has been done on the structure, it is now, according to Estelle Bertrand, among the "best-known enclosures from antiquity."
The monument has been classified as a historical monument since 1862 and has been a candidate for UNESCO World Heritage status since 2016.
History during antiquity
General context
From origins to the crisis of the 3rd century Urban enclosures serve three distinct functions: they delineate cities, defend them, and demonstrate their power. In the context of the Roman peace, few enclosures were constructed in Gaul. Security was ensured by a cohort in Lyon and legions positioned along the Rhine. The number of cities with enclosures was relatively limited, with only nineteen examples identified before the mid-3rd century. These were largely situated within the context of "symbolic remilitarization" and for prestige purposes. These structures were "public monuments with an ostentatious" and symbolic character. The majority of chief towns were not equipped with enclosures.
Following the assassination of Alexander Severus in 235, a crisis commenced that persisted until 284. This crisis encompassed political, military, and economic dimensions, as well as a period of heightened insecurity due to mounting pressures on the Empire's borders and the eruption of peasant revolts. Additionally, it was accompanied by a climatic and epidemic crisis. These crises precipitated a multitude of economic and civic transformations, leading to an overall fragility in urban life and a population decline.
Some public edifices were deemed uneconomical to maintain or were rendered superfluous as a consequence of these alterations.
Late Empire Following the conclusion of the crisis, a comprehensive reorganization commenced and persisted under the leadership of Diocletian and Constantine. Extensive administrative, economic, and political reforms were initiated, including the division of Roman provinces to enhance administrative efficiency. This reorganization persisted until the 4th or early 5th century, according to Joseph Guilleux's analysis published in 2000.
The late enclosures were associated with a "new military, political, and administrative context", with a notable reduction in the area protected compared to the previous extent of cities. This reassertion of control was exemplified in Rome by the construction of the Aurelian Wall, which spanned 19 km. Civitas capitals were equipped with them, as well as other sites that assumed new administrative or strategic roles. The movement commenced in the last quarter of the 3rd century.
The Roman military system was subsequently reinforced, a system of fortified cities was established within the Empire, and this constituted "the most remarkable element of this system." The Rhine and Danube borders underwent significant reorganization, and the chief towns of cities were equipped with enclosures, which symbolized the "restored order and renewed power of Rome."
The construction of enclosures, which exhibited considerable variation in terms of the areas they encompassed and the nature of the structures erected, continued until the fifth century. By the midway point of the fifth century, the majority of capitals and secondary towns had enclosures. These constructions, which were likely undertaken with the Emperor's authorization, incorporated elements from High Empire structures and served as a symbol of prestige, even though the enclosed areas were smaller than the territories encompassed by the towns.
During the 4th and 5th centuries, there were periods of both turmoil and relative calm. At the beginning of the 5th century, the era of "real invasions" began.
Local context
Vindunum and history until the High Empire
The city developed on the plateau of Sargé, situated between the Sarthe River and one of its tributaries, the Isaac. The topography is characterized by a steep gradient towards the Sarthe River, which gradually becomes gentler in the opposite direction. On the Sarthe side, the site of the current enclosure was protected from flooding, despite the absence of river dikes. This was due to the fact that the Sarthe River could serve as a natural defence against potential enemies and as an economic asset.
The site of Le Mans was occupied between the 8th century BC and the 5th century BC. As early as Ptolemy (Geography, II, 8), the place was known as the capital of the Aulerci Cenomani. However, the presence of an oppidum on the site remains uncertain, despite the discovery in 2010 of a mid-1st century BC occupation interpreted as a water sanctuary, a "small isolated complex."
After the Roman conquest, the city was incorporated into the newly established Augustan organization of Gallia Lugdunensis. The available evidence suggests that knowledge of the High Empire city is "delicate." The town is believed to have taken shape at the beginning of the Common Era. By 50 AD, the town occupied approximately 30 hectares, while by the end of the 1st century and the beginning of the 2nd century, this had increased to approximately 40 hectares. The site was modified by the installation of terraces, which were constructed to facilitate urbanization.
The period of greatest urban vitality for the city was from the Flavian dynasty to the 3rd century. The ongoing Romanization resulted in a transformation of lifestyle and urban display during the 1st and 2nd centuries. Some inhabitants were granted Roman citizenship as early as the mid-1st century. The city acquired institutions based on the Roman system, and a monumental temple dedicated to Mars Mullo, which was , was constructed at the end of the 1st century. The city then had monumental decorations intended to mark its political, religious, and leisure role; furthermore, it may have been equipped with a river port.
The city's area was estimated to be between 70 and 80 hectares by Joseph Guilleux in the 2nd century. However, recent syntheses have proposed a more modest figure of approximately 60 hectares, dating to around 200.
Contraction of the city and history in the Late Empire
Crisis
In the 3rd century, the city underwent a name change, becoming known as Civitas Cenomannorum. During the period of turmoil that followed the Gallic Empire's establishment in 260 CE, the city was incorporated into the empire.
The expansion of the city ceased at the beginning of the third century. The area was 45 hectares in the mid-3rd century, and it still encompassed approximately thirty hectares at the end of the century. The city exhibited a pattern of alternating abandoned sectors with other still-occupied sites, such as the entertainment building or a tavern. The period between 270 and 280 saw a notable decline in the extent of inhabited areas, except for those situated in proximity to the Sarthe. This period also marked the cessation of craft activities. Unoccupied areas were either in a state of disrepair or returned to agricultural use.
Construction of the enclosure The construction of the Roman enclosure of Le Mans was a strategic necessity for the protection of the city. The question of the military role of the city and the enclosure, whether they constituted "part of a larger system" or an autonomous system, remains unresolved. The enclosure of Le Mans is part of a group of structures intended to protect roadways. It is possible that a garrison was present. The structure also aimed to affirm the city's power and wealth.
The enclosure has been long dated to the reign of Diocletian, between 270 and 310. Joseph Guilleux's thesis proposed a date of approximately 285 based on the results of archaeometric analyses of bricks that have been re-examined. The most recent estimates from Inrap, from 2018 to 2019, suggest a date range of 320 to 360 for the entire structure, with the eastern part dating to within this range.
The decision to construct the enclosure is thought to have been made at the end of the 3rd century and the beginning of the 4th century. However, the evidence available does not allow us to determine with certainty the circumstances surrounding the preparation phase. The archaeological data suggest that the enclosure was built to a high standard and that the planning and execution of the work were carried out methodically and thoroughly, without undue haste.
This decision was made by the local authorities with the agreement of the imperial authority. The enclosure also serves to mark the restoration of the Empire after a period of turmoil, during which it was necessary to mobilize labor and financial resources. These may have been derived from local euergetism and a special tax or imperial exemption, or even from the reallocation of taxes and levies. Euergetism had not been practiced in the Gaulish territories since the 3rd century.
As Joseph Guilleux has observed, the enclosure allowed the city to maintain its "tradition of domination" over a territory. The construction represented an opportunity to reaffirm the status of the capital and the position of the local elites.
The plan was drafted by an architect or engineer, a "specialist in military architecture", who was either a member of the army or an imperial official. It included the requisite gates and posterns and considered the existing road network, as well as the necessities for amenities such as sewage and rainwater systems. The civic center was probably incorporated into the enclosure.
The construction project spanned a minimum of three to five years and employed at least 200 masons. It is reasonable to conclude that the project could have taken up to twenty-five to thirty years if fewer workers were employed. Joseph Guilleux estimated that the construction took approximately ten years. For comparison, the Aurelian Walls in Rome were built in five to ten years. The project had a significant impact on the local economy, mobilizing a diverse range of trades. The workforce likely included both soldiers and locals subjected to forced labor.
Some neighborhoods of the city, as well as public and private buildings, were razed to facilitate the construction and implementation of the project. The clearances, estimated to encompass between 4 and 13 hectares, may have spanned "several tens of meters."
Urban transformations and the end of the Empire