The police headquarters and the Institut national de recherches archéologiques préventives open a window into the history of Paris

The history of the Cité begins with the gradual emergence of a sand bank in the Seine river bed starting in the Neolithic period. The archaeologists, directed by Xavier Peixoto, are working to obtain a better understanding of the geological formation of the Ile and its evolution over time. The research will be possible in the deepest layers of the site once all of the archaeological remains have been uncovered.

The emergence of the urban phenomenon in Paris (the distant origins of the Gallic Lutèce) has always played a major role in history and is the subject of debate in the archaeological community. Recently, some archaeologists proposed that the Cité of the Parisii was implanted in the meander of the Seine at Nanterre. In effect, though Cesar placed Lutèce on an island, no remains from the Gallic period have been discovered on the Ile de la Cité.

At the beginning of the Gallo-Roman period, the center of Lutèce was developed on the Sainte-Geneviève mountain. The Ile de la Cité was then the site of craft and commercial activities linked to the river port. At the beginning of the 4^th century, the Ile was fortified and surrounded by ramparts. It then became the center of the city. Earlier excavations on the rue de Lutèce had already revealed modest constructions and a street connecting the basilica of the flower market at the "Palais”, a large administrative or military building, now buried beneath the Palais de Justice.

The current archaeological excavations are being conducted at the location of the modern church of Saint-Éloi, reconstructed in 1632 by order of the Barnabites. In 635, under the direction of Saint-Éloi and the protection of King Dagobert 1^st, a female monastery was founded, dedicated to Saint-Martial of Limoges, today known as Saint-Éloi.

Since mid-April, the archaeologists have revealed the south-east angle of the nave of the church of the Barnabites and part of its cloister. Their task is to find all of the elements related to the history of this religious establishment since its Merovingian origins. Its robust masonry nearly obliterated the earlier layers. In this structure, Medieval lapidary elements were re-used in the foundations of the 17^th century church. Inside the cloister, Medieval graves are preserved.

Around ten of them, attributed to the 13^th -14^th centuries are currently being excavated. Some contain incense vases. These graves are attributed to a period during which the monks of Saint-Maur-des-Fossés overcame the nuns, who were sent away for supposed misconduct in 1107.

As of today, no artefacts linked to the church and cemetery of the nuns have been found. If confirmed, this absence of evidence would support the hypothesis that the original church founded by Saint-Éloi occupied the location of the Saint-Martial oratory, which no longer exists, erected a few dozen meters to the east of the current excavation.

The Antique layers have not yet been excavated. The oldest layer currently identified is five meters below the current ground level. It corresponds to a flood deposit containing pottery dated to approximately the beginning of the modern era. Other more ancient layers could thus be present.