Between the 9th and 10th centuries founding ecclesiae private became an effective tool for strengthening the role of some families within the city structure. In some cases it would have proved to be a real investment that is particularly effective in increasing the prestige and finances of particular factions. Social prominence, broadening of the basis of political consensus proved to be a strict consequence of the direct control that the family and the heirs of the founder exercised over the possessions of these entities. It was the specific needs of managing patrimonial complexes of this type, continuously enriched by donations and testamentary bequests, to allow the intensification of relationships and consents around the founding family, with the involvement of an increasing number of individuals in economic and in the political instances of the same.

Emblematic is the case of Prince Guaiferio who built his residence on Plaium Montis around the middle of the 9th century and founded the church of San Massimo next to it. In the project of founding an ecclesia, which also supported a private residence, the aim of offering a prestigious residence to one's descendants is implicit, but also that of providing it with a predominant role within the noble citizen groups, which have become, in that historical moment, the real arbiter of the Salerno political scene. Guaiferio, who was not of Salerno origin, would have used San Massimo to increase his private heritage and above all to guarantee his descendants, precisely through the mechanisms put in place by the management of the ecclesia, a progressively wider space in the balance of power citizens. The Plaium Montis, particularly rich in water resources, strongly characterized compared to the rest of the city because it is located at a higher altitude, served by a road axis that led from Porta dei Respizzi to the heart of the city, was, for these purposes, the ideal site . To the power of St. Benedict, Guaifero contrasted the economic importance of his foundation, made even more influential by the presence of an altar dedicated to the apostle Bartholomew.

The foundation of another private ecclesia, also of a princely matrix, must be interpreted in the same logic, that of Santa Maria de Domno, destined, like San Massimo, to become a new fulcrum of the urban fabric, this time shifted towards the sector southeast of the Arechian city. The ecclesia, born by the will of Princess Sighelgaita, was built at the end of the 10th century, near the stalls that ran parallel to the "muricino": a wall segment parallel to the walls built under the principality of Grimoaldo to reinforce the line of defense along the coast. The space included between these two walls, destined to later become the Via Carraria, was the main route of the inhabited sector grown along the coast, directly connecting the eastern part of the city with the western one. In Sicardo's projects, the impetus for the development of a mercantile economy should have originated from this area, and thanks above all to the stimuli offered by the settlement of an Amalfi community. The specialization of this city sector in relation to the manufacturing activity and, in any case, linked to an exchange economy is marked by a more mature phase at the end of the 10th century, when, next to that western strip of coast that Sicardo he had destined for the Amalfitans, or the vicus Santa Trofimena, a Jewish community also began to settle, between "wall" and "muricino", as this space is often defined in documents, giving rise to the neighborhood that will be called Giudaica.

The progressive growth of the coastal districts and the importance assumed in the hierarchy of routes by the Via Carraria, which from east to west crossed the entire town, from the mouth of the Fusandola to that of the Irno, explains the choice made for the foundation of Santa Maria de Domno, clearly denouncing the now complete transfer of the gravitational point of the city along the coast line. The founders of the ecclesia, despite being part of the consortium that decided the election of the rector of San Massimo, did not consider it appropriate to renounce their own ecclesiastical foundation. Evidently the location of San Massimo, which by now remained far from the most vital districts of the city, did little to satisfy those demands of visibility and social prominence with respect to a new reality, immersed in the vital heart of the new economic pole of the city.