Prior to the construction of a shopping center, the excavations of the place du Jeu de Paume in Beauvais were an opportunity to study an nearly 2 hectares urban environment, more than 5 m of stratigraphy and to study occupations ranging from the Middle Neolithic II to the Second World War.

Thus, for the first time in downtown Beauvais, evidence dated between -3350 and -3000 testifies to an at least temporary occupation of this sector of the Thérain Valley during this period.

We then had to wait until the first half of the first century of our era to find evidence of an occupation, which lasted for two and a half centuries. First ditches were required to drain the marsh. Then a residential area developed, served by two decumani and a cardo. These houses, with peristyles and ornamental basins demonstrate classical Roman architecture and with ceramics, instrumentum and painted plaster testifies to the presence of a wealthy population.

Large buildings, extending about 120 m from north to south, were erected during the second half of the 2^nd century. They are evidenced by a monumental gallery with a portico and a fence, undoubtedly delimiting a garden. Though their function is not currently known, it is likely that they were part of the group of district public buildings, including one discovered on the site of the Hôtel-Dieu and the sanctuary of Mont-Capron. The houses of the Place du Jeu de Paume were gradually abandoned from the middle of the 3^rd century, as were the large buildings. The total abandoning of the district was complete at the end of the same century. It confirms the retraction of the urban space of Caesaromagus at the beginning of late Antiquity.

There is no evidence of an occupation of the site between the end of the 3^rd century and the end of the 7^thcentury, except for the continuity of use of the two main east-west roads. Between the end of the 7^th century and the end of the 10^th century, a small funerary complex of ten individuals was created near the northern axis. From the eleventh century, the area was again regularly frequented with the recovery of materials from the ruins of the ancient monuments, which intensified throughout the 12^th and 13^th century, in parallel with a settlement in the northwest of the site. From the end of the twelfth century or the very beginning of the thirteenth century, the site was completely redesigned with the construction of a defensive system. A portion of the walled enclosure 153,75 m long was cleared, with four buttresses and two semi-circular towers. The rampart was reinforced by a defensive ditch fed by the waters of the Thérain. Their crossing lay in front of a door built at the level of the old east-west axis, using a bridge with two arches. In the second quarter of the 15^th century, faced with the evolution of artillery, the defensive system was strengthened and adapted. At the front of the door, a massive quadrangular platform or artillery tower was built. Upstream and downstream of the bridge, two east-west oriented walls were constructed corresponding to what were then called « boulevards », a new type of defensive structure.

Beginning in the 1540 s., a vast project was undertaken to strengthen and protect this sector, in the face of new threats of war. The construction of a new south-facing gate and widening of the ditch resulted in the construction of a new bridge with six arches, two sleeper bridges and a drawbridge. The defensive ditch, which was last used in the 16^th-17^th centuries, had an estimated width of 20 m to 25 m and up to 34,70 m at bridge level.

An essential element of the new defensive system was a bastion/stronghold on the site of the old medieval gate. Its southern facade, revealed for over a length of 44,20 m, was reinforced at the rear by several buttresses. A 110 m² lower room, probably used as an ammunition depot and shelter for the garrison, as well as a gunnery was positioned on the south flank and ensured the protection of the bridge. The bastion also contained an internal water circulation system.

At the beginning of the 18^th century, modifications took place that resulted in the removal of the sleeper bridges, drawbridge and gunboat, reducing the bridge to its six arches. In 1732, the city decided to flatten the non aedificandi space in front of the counterscarp to plant trees and create a place du Jeu de Paume.

In the last quarter of the eighteenth century, to address sanitary problems and help with the water management of the ditch, a collector ditch was built between the bastion and the bridge at the level of the second arch. Its development led to the closure of the three arches still preserved today. The work of dismantling the fortifications, at the level of the gate, began in 1803 and ended in 1815. The city wanted to create large boulevards and walks around the city. The whole site was filled and levelled. A public square was created and decorated with a fountain and a bandstand.

From the summer of 1940, following the bombings that destroyed 80 % the city, the place du Jeu de Paume housed barracks and temporary dwellings, which are associated with trenches-shelters of the passive defense. In the late 1960 s., the last barracks were razed to the ground. The square was again filled and levelled. Since the 1970s, it has hosted a large parking lot and nowadays, the Jeu de Paume shopping center.

This archaeological operation was therefore an opportunity to enrich considerably the knowledge of the history of Beauvais, and thus complete the plan of Caesaromagus with the rampart of Philippe-Auguste.

Traduction : John Lynch