This is the century of the first crusade and of the capture of Jerusalem (1099) launched by Pope Urban II in full-term renewal of the Church.

Starting with the eleventh century the Italian cities, with the help of the crisis of the Empire and of the Papacy living in parallel, began to break away from both the central political power and from that of the church and gave rise to independent forms of political power who took the name of the Communes.

In the north of the peninsula, between 1155 and 1190, Emperor Frederick I, called Barbarossa, tried to restore the rule of the Commune on, but was defeated in 1176 in Legnano, in the course of an epic battle in which they met the Imperial troops and the rebel communities, allied in the Lombard League.

Next to the Battle of Legnano is the peace of Constance, signed in 1183 and which the claims of autonomy of municipalities are essentially recognized.

Almost simultaneously the Kingdom of Sicily was forming. In 1059 Robert Guiscard obtained from Pope Nicholas II the title of Duke of Apulia, which included the present dukedom of Puglia, Basilicata, Campania, Calabria and part of Sicily (still in the hands of Muslims). In 1061 Roger of Hauteville, Robert's brother, landed at Messina and invaded Sicily, being able to arrive at Palermo in 1076. With the son of Roger, Roger II, the two crowns were united to form a kingdom of substantial size, the Kingdom of Sicily.

Between 1200 and 1300 the Italian Municipalities knew centuries of great cultural renaissance: there are many names of Italian literature that may be related to these two centuries, from Dante to Petrarch, Boccaccio, Iacopone da Todi, from Formosa to Guinizzelli.

The second half of 1200 and 1400 witnessed the gradual emergence of the Lords and the changing policy of many municipalities in northern Italy, of which the most famous are those of the Medici in Florence, the Sforza in Milan and Pesaro and the Gonzaga in Mantua.

The Lordships, who later turned into real crown prince (even if with different names), helped to mark the final death of the Emperor, and the other great medieval institution, the papacy, not fared much better: in 1305, following the descent of King Philip of France in Italy and the defeat of Pope Boniface VIII, the papacy was moved by Pope Clement V at Avignon, where it spent the next 70 years.

After 1300 time signals the gradual blossoming south of Naples under the Angevin dynasty, whose fortune lasted until 1342 when Alfonso V of Aragon, defeated his rival Rene d'Anjou decreeing the effective end of the Kingdom of Naples and the Kingdom of Sicily.

The Italian’s 1400 was characterized mainly by a long series of wars and struggles between those who had been transformed into real countries: key roles of this rivalry was mainly the Duchy of Milan and the Republic of Venice, engaged since 1300 in expansions locally and on a large scale.

In contending for the dominion over the seas were, however, the ancient maritime republics, especially Pisa, Genoa, Venice and Amalfi ousted from contention and fought repeatedly for the control of the Tyrrhenian Sea.

With the final decline of the Byzantine Empire and the fall of Constantinople (1453), Venice's main rival to control the Adriatic, the Venetian could dedicate to land expansion, coming soon in conflict with the interests of the Duchy of Milan .

The conflict between Venice and Milan, brought the two rivals to sign a truce in Lodi in 1454, setting on the Adda river the border between their territories and to dispense with further expansionist aims.

The Peace of Lodi granted Italy a condition of peace for the next 40 years, balance that favored the emergence and development of the Italian Renaissance.