Restoration of the building provided the occasion for an archaeological investigation in the central sector (2006) and then in the presbytery (2007-2008) of the parish church of Santi Ruffino e Venanzio at Sarezzano.

The church, despite its present aspect, mainly the result of post-Tridentine interventions (the most recent in the last century), has ancient and illustrious origins. These are attested by several elements: firstly, the presence here of the Codex Purpureus, the famous 5th-6th century book of gospels, and also of a funerary inscription of the abbot Rufinus. Datable to the 6th century, it indicates the existence of a monastic community (Ruffinus was the abbot) and a church on the site of the saint’s burial. The building’s continuity of use is attested by a number of early medieval sculptural elements (datable on a stylistic basis to the late 8th century). A slightly later inscription dating to the 7th-8th century confirms the devotion to Ruffino, later flanked by Venanzio.

The excavation documented several walls dating to the first early medieval phase: they belonged to the outermost foundation of the central apse and the juncture with the side apses, built in squared stone blocks, without brick courses. Between the end of the 11th century-beginning of the 12th century, the church was completely reconstructed in the Romanesque style. From this phase, only some parts of the standing walls survive, in particular on the south side and the facade (originally a hut-like facade), where traces of the pilasters joined by suspended arches remain. The excavation provided new data on the layout of the eastern end of the Romanesque church: in particular, the large crypt was uncovered that occupied about half of the church’s length and was accessed via a double stairway from the eastern aisles. Half columns divided the lateral walls, while there were only negative traces of the small columns supporting the cross vault. West of the crypt an interesting underground space was identified, masonry-built and plastered. This chamber has been interpreted as a “_memoria_”, destined to house the relics of the titular saints (one of the ancient reliquaries was identified in a stone arch conserved inside the church). The only access to the chamber was a narrow window through which the faithful could contemplate the saints’ remains.

The excavation also documented the building’s later transformations: new terracotta paving (replacing the Romanesque stone floor) in the second half of the 15th century and then the complete reconstruction of the building, reduced to one nave with quadrangular choir, between the second half of the 16th century-beginning of the 17th century. In this phase, the crypt was demolished and, having recovered a number of architectural elements (the small columns), filled with rubble. From this period onwards, the custom of burying inside the church – already attested in the late medieval period – determined the complete occupation of all the internal spaces – and consequently – the destruction of a part of the archaeological stratigraphy.