The date of origin of the Conventazzo is currently not known. Generally, it can be noted that the type of the central building type in Italy is based on (Late) Antiquity roots. In the 4th to 5th centuries this building type is characteristically for baptisteries and memorial chapels. Architecturally, the Conventazzo style does not currently classify the building. The date of origin can be assumed in Late Antiquity up to the period of the 6th century, certainly before the middle Byzantine period. For sure the octagon can not be dated as Norman.

Even the meaning and function of Conventazzo have not been clarified yet. This probably can only be done by archaeological means. One might think of a memorial chapel or a baptistery. However, in the latest case the Conventazzo's dimensions are in comparison to those oft the church in the Southeast surprisingly large.