The area surrounding Romilly has been inhabited since at least the Neolithic period (4000 BC), as is shown by the numerous knapped flint tools found during initial machining. Remains from the Bronze Age (1800 BC) and the Gallo-Roman period (1st century BC) have also been discovered. The main objective of the archaeologists, however, is to study the Early Mediaeval occupation on Liberation Street, characterized by the presence of silos, domestic ovens and granaries. This habitat is limited to the north by a cemetery of the same period.
At the end of the 11th century, William Fitzosbern, a powerful vassal and loyal companion of William the Conqueror, gave the land of Romilly-sur-Andelle to the Benedictine Abbey of Lyre, which he had just founded. This latter created the priory of Saint-Crespin. The cemetery was then translated further east (next to the current location of the Church of Saint-Georges, constructed at the transition from the 11th to the 12th century). Since there is no written description of this religious ensemble, the archaeological excavation will provide important information concerning the organization and evolution of the priory until its abandonment.

The first church was constructed in two phases. A first circular building was joined to a rather flat apse. A second circular building then intersected the first one, giving the original ensemble a rather unusual clover like form. This first edifice is over two relatively large shelly limestone sarcophagi topped with two bâtière (saddle-roof) covers.
Between the 10th and 12th centuries, a new church was constructed over the preceding one. It was larger and comprised a rectangular nave divided into two bays supported by flat buttresses, and an apsidal choir. The high quality stonework is in opus spicatum and the presence of a wall between the nave and the choir could indicate the existence of a semi-dome vault covering the sanctuary.

During the first excavation season, forty burial pits organised in three levels were discovered. There were no finds in these graves, although a few excavated during the evaluation, nearer the centre of the cemetery, yielded objects characteristic of the Early Middle Ages. This excavation was preliminary to a much larger operation concerning nearly the entire cemetery, as well as the buildings, which began in July 2006.
The 300 graves currently excavated contain adults of both sexes as well as children. On the periphery of the cemetery, the children are all more than two years old. In contrast, numerous very young subjects (less than two years old) were buried closer to the church, though their number remains for the moment below the natural infant mortality rate for the period.
The oldest graves, located in the southern part of the cemetery, date from the 6th century. Many tombs (150 to 200) date to the end of the 6th and the 7th centuries, half with objects in place (pottery, fibulae, scramasaxes, etc.). The dates of the more recent tombs are determined by the construction of the first conventual buildings. The cemetery was abandoned around the 10th to 11th centuries when the Benedictine priory was established.
Future physical anthropology analysis will allow us to address the question of distribution by age, sex, morphology and health of the population. The palaeogenetic analyses will provide information about family groups and the origins of the cemetery population.

During the 14th century, major construction work transformed the church into a manor. The nave remained standing while stonework was robbed and the choir was levelled. The sanctuary was replaced by an oblong building with a stair tower in the middle of its northern façade. The presence of a fireplace, a direct access to the storeroom, and a stair tower seems to confirm the change of use of the former nave.
Several annexes were added. To the west, a contiguous building was added, though of this only the large cellars now remain. An excavated space of 50 m2, where food was stored, was also found. A little later, during the 14th century, an enlargement was made under the manor to the east. A small, well preserved, vaulted cellar, supported by two arches, was linked to the large storeroom to the west by a small stairwell. To the south, a small barrel-vaulted corridor followed by a sloping passage led into the manor. This is how provisions must have been carried to the kitchens which were located in a building attached to the south of the manor. They are very similar to the kitchens of Vatteville-la-Rue Castle (Seine-Maritime), with a stone slab sink, a large fireplace and a bread oven. Finally, to the north of the manor, a magnificent, very well preserved 14th century barn was likely used to store the harvests. To the south of the domain, two circular buildings were found . The priory was abandoned in the 17th century.

The excavations are financed by the National fund for preventive archaeology (FNAP)