1.1 The International Institute of Ligurian Studies and the University of Genoa’s Department of Medieval Archaeology recommenced investigations on the cathedral of S. Maria in 2007. The new phase of research – fifty years on from those undertaken by Nino Lamboglia – involved over fifty people from the university and the Civic Museum of History and Archaeology. The excavation, directed by Carlo Varaldo and Rita Lavagna, examined an entire room of the House of the Colonels and the pre-existing habitatione of the Citadel Commander, over an area of circa 100 m2.

1.2 The excavations began at a floor of stone basoli and brick datable to the final phase of use of the rooms of the House of the Colonels, that is the phase which concluded with the demolition in the 1940s.
The various phases of flooring in the room were documented and removed, bearing in mind the successive phases of maintenance and repairs which between the 17th and 20th centuries had led to the formation of a composite floor level. The original and earliest phase, datable to between the end of the 16th-beginning of the 17th century, was constituted by an extremely worn brick pavement with much evidence of relaying and repairs.

Below this original floor level there was an extensive layer of very compact detritus with a mainly lime matrix. The finds recovered indicated that this deposit had formed in the 16th century. The demolition dated by the written sources to the end of the 16th century was extreme. Only a small part of the original deposit relating to the medieval cathedral was preserved below the building site phase for the construction of the rooms belonging to the buildings inside the Genoan citadel.

In the southern part of the excavation this sequence covered the razing of a thick wall on an east-west alignment. The wall was only preserved at foundation level and may be identified as a perimeter wall of the nave of the cathedral of S. Maria. There were no traces of the cathedral’s floor, but only part of the beaten mortar make up. Both inside and outside the nave – below the layers relating to the construction site of the end of the 16th century – part of the bedrock appeared which had been artificially levelled.

In the north part of the excavation, in correspondence with the central nave, a beaten floor surface and a masonry-built burial loculus were identified, but above all two steps emerged which led down to the crypt. The traces of earlier phases and structures were very limited. A wall bonded with rough mortar rich in charcoal inclusions may be interpreted as a perimeter wall from one of the cathedral’s phases. A number of burials in earth graves showing clear signs of reuse, can be placed within this phase.

1.3 The archaeological analysis of the phases relating to the Habitazione of the citadel’s commander and the House of the Colonels has produced important elements for the reconstruction of the phases which date from the demolition of the cathedral of S. Maria to the present day. The elements acquired for the reconstruction of the building phases of the cathedral to a large degree integrate the data from the excavations and the previous investigations. Based on this body of data, which is totally complementary to that from the written sources, reconstructions of the cathedral’s plan and occupation phases between the 12th and 16th century have been elaborated.

A perimeter wall and a cemetery phase belonging to a building given a preliminary date in the late Middle Ages was uncovered. This late medieval phase may be linked to the presence of architectural sculptural elements of Lombard and Carolingian date, recovered during the course of the investigations.

The layers that can certainly be dated to the late antique period – in the excavated area – were quantitively and qualitatively very limited. These elements document the occupation of this part of the Priamàr hill during the Byzantine period, even though they cannot be directly associated with the presence of a church. Only the continuation of the excavations in 2010 and the widening of the excavation area will clarify whether:

- the Byzantine occupation phase (6th-mid 7th century A.D.) was associated with a primitive church whose structures have yet to be identified. – the construction of the cathedral of Santa Maria should be dated to between the late Lombard period and the Carolingian period, as suggested by the chronology of the marble architectural sculptures recovered during the excavations.