We know that the area had already had a sacred character for some time since the documentation tells us the presence of the churches of Santa Maria Dei Genitricis, San Giovanni and, probably, San Matteo. In this regard, De Simone identifies a different location for the church of San Matteo and places Santa Maria Dei Genitricis, identifying it with the early medieval cathedral, within the structures of the Temple of Pomona, later included in the nearby archiepiscopal complex of the 11th-13th century. Therefore the A. claims that the old cathedral was not demolished to make way for the new one, but that having fallen into disuse it was incorporated into other factories.

If De Simone's hypothesis were confirmed by future archaeological investigations, the choice of the place where to build the Norman cathedral would appear not only conditioned by contingent factors, but rather suggested by the symbolic values ​​of the site, through which Guiscardo, offering from his own heritage , proposes itself to citizenship as Patron Urbis, creating, at the same time, a work that, due to the unprecedented scale of intervention, was able to worthily enhance its prestige as "Dux romani Imperii maximus triumphator", as stated in the epigraph of the foundation of the same cathedral.

.To dictate the lines of urban expansion, the need to occupy the only free spaces left within the Arechian walls also contributed in a decisive way. And this is as true for private construction as it is for large public interventions, as well as for the new seats of power. If we compare the dimensions of the cathedral which is 78 m long. and wide from 31 to 36 m., in addition to those of the quadriportico, 35.9 m long. and 33.3m wide, with the orographic model of the historic center, one realizes that even for merely displacement problems the architects did not have other spaces that were sufficiently large and steep. A check of the current elevations, along the external perimeter of the Duomo, however, makes us perceive how the architects were forced to create a powerful terraced artificial embankment, conformed to the contour lines, and how they tried to overcome the many problems of slope stability.

Problems that have left extensive marks in the building history of the building: already around 1443, the first restoration works were carried out, with the replacement of some columns by masonry pillars and with the construction of pillars to support the external side of the right aisle; between 1471 and 1482 the central apse was consolidated. In 1554 the church was again in a precarious state so much so that Archbishop Seripando turned to Emperor Charles V for grants, and so during the last quarter of the 16th century there were various partial interventions for the repair of the roofs and for the replacement of other columns with pillars.