honestly, from the way the question is posed, it is difficult to understand what result you realistically expect to obtain, for a series of reasons, the first is that after the disintegration of the administration and then of the central authority of the first Carolingians in Italy, the peninsula north of Rome ( but also in particular cases in the south of the Urbe ) was extremely fractured into various smaller entities ( in turn governed by a local assembly usually headed by the city bishop and followed by the nobles and finally the first traders/artisans ), these political formations were extremely unstable and very quarrelsome with each other, but all fairly agreed that they still wanted to be part of the ideological umbrella of the Roman Empire ( even if they badly tolerated the Emperor's pressure to enforce his authority in the region, but the same thing is equivalent also due to papal attempts ) with the passing of the centuries we witness an important first phase of territorial consolidation which sees Italy being roughly divided into 4 types of state formation: the kingdom of Sicily ( highly centralized and comprising almost 2/3 of the peninsula ), the pontifical state ( which is the continuous large-scale evolution of the episcopal power within the municipal assembly ), followed by its exact opposite, namely the municipal cities, which can be of a mercantilist or maritime type ( as Genoa, Amalfi, Pisa and Venice ) mainly economic and Thalasocratic powers is that they use the army on the ground as a mere additional defensive stratagem, preferring to focus on their geographical position which allows them to resist long sieges, to conclude we have those municipalities where the factions in struggle they compete for power ( they are usually part of the HRE, it is from these conflicts that the Guelph and Ghibelline parties were born ), the main one among these is Milan ( it must be remembered that the Lombard league was originally created to counter Milan's expansionist aims ), other important locations that fall into this category are Florence, Bologna ( which became papal territory only in the 13th century ), Verona, Pavia, Crema, Siena, Arezzo etc, it is this extreme competition between all of them that led to the formation of the concept of balance of power, i.e. that when an Italian city / potentate / kingdom became too powerful, a coalition was usually formed to defeat it: as in the case of Milan ( victim of this policy in 3 cases, first during the municipal era, then under the government of the Visconti / Sforza ) the Verona of the Scaligeri, Venice with the war of Cambrai, the Hoffenstauffen Emperors ( in particular the Puer Apulliae, Frederick II, who was one of the closest to creating a possible proto national unification ) without wanting to delve into the problem of what to do with the papal state ?, given that it was an important piece of the Italian social, political and cultural fabric, is that any attempt at unification would sooner or later have come to terms with Rome, it is history that demonstrated several times that it was ALMOST never good for those who challenged the Pope ( Frederick II always teaches ), certainly there were moments in which a state could become an aspiring hegemon but usually if the local alliances were not enough to make it desist, the Italians usually resorted to asking for foreign intervention ( which then promptly proved to be a bad idea for the whole peninsula.... Coff .... France.... Italian wars .... Coff )