Even though the western Roman Empire had fallen apart by 476 CE, the great cities of Italy survived in better shape than Roman cities elsewhere in the empire. Likewise, the feudal system had never taken as hold as strongly in Italy – there were lords and vassals, but especially in the cities there was a large and strong independent class of artisans and merchants who balked at subservience before lords, especially lords who did not live in the cities. Thus, by 1200, most Italian cities were politically independent of lords and came to dominate their respective hinterlands, serving as lords to “vassal” towns and villages for miles around.
Instead of kings and vassals, power was in the hands of the popoli grossi, literally meaning the “fat people,” but here meaning simply the rich, noble and non-noble alike. About 5% of the population in the richest cities were among them. The culture of the popoli grossi was rife with flattery and politicking, since so much depended on personal connections. Since noble titles meant less, more depended on one’s family reputation. The most important thing to the social elite was honor. Any perceived insult had to be met with retaliation, meaning there was a great deal of bloodshed between powerful families - Shakespeare's famous play Romeo and Juliet was set in Renaissance Italy, featuring rival elite families locked in a blood feud over honor. There was no such thing as a police force, after all, just the guards of the rich and powerful and, usually, a city guard that answered to the city council. The latter was often controlled by powerful families on those councils, however, so both law enforcement and personal vendettas were generally carried out by private mercenaries.
Another aspect of the identify of the popoli grossi was that, despite their penchant for feuds, they required a peaceful political setting on a large scale in order for their commercial interests to prosper. Thus, they were often hesitant to embark on large-scale war in Italy itself.
Likewise, the focus on education and culture that translated directly into the creation of Renaissance art and scholarship was tied to the identity of the popoli grossi as people of peace: elsewhere in Europe noble identity was still very much associated with war, whereas the popoli grossi of Italy wanted to show off both their mastery of arms and their mastery of thought (along with their good taste).
The central irony of the prosperity of the Renaissance was that even in northern Italy, the vast majority of the population benefited only indirectly or not at all. While the lot of Italian peasants was not significantly worse than that of peasants elsewhere, poor townsfolk had to endure heavy taxes on basic foodstuffs that made it especially miserable to be poor in one of the richest places in Europe at the time. A significant percentage of the population of cities were “paupers,” the indigent and homeless who tried to scrape by as laborers or sought charity from the church. Cities were especially vulnerable to epidemics as well, adding to the misery of urban life for the poor