Twelve hundred and fifteen years of history retraced in almost six hundred pages organized in thirty chapters. These numbers are not frightening. Gatto’s work on medieval Rome can be read in one breath, transported by weight in a period of the Eternal City often unjustly neglected. It is the epoch that marks the affirmation of the Christian religion in imperial Rome and the development of the spiritual and temporal power of the Church, which will replace the declining power of the emperor in the West. To consistently cover this crucial period in the history of the city, the author’s definition of the Middle Ages is broader than the usual one: instead of starting with the fall of the Western Empire in 476 (deposition of Romulus Augustulus), the discussion starts from the triumph of Constantine in Rome (312); the end is placed with the sack of Rome by Charles V (1527), thirty-five years after the traditional date of the discovery of America (1492). During the principality of Constantine, Rome was at its peak. The new position of the Christian religion, sanctioned by the edict of tolerance of Milan of 313, was reflected in the urban planning of the city with the construction of the first great basilicas, such as that of St. Peter on the Vatican hill and that of St. Paul, on the via Ostiense. With the transfer of the capital of the Roman Empire to Byzantium, in Asia Minor, Rome ceased to be the political center of the empire, but began its affirmation as the most important religious center of the Christian world, as the final residence of Peter, the first head of the Christian community after the death of Christ. Although the successors of Constantine did not lack economic and military support for the city of Rome, the shift of the political center of gravity of the empire to the East left Rome exposed to risks no longer known for a long time . In 410 the Goths of Alaric entered Rome and sacked it, eight hundred years after the aggression of the Gauls of Brenno. Other threats were directed against the city, with Attila’s Huns and Genseric’s Vandals, against whom the head of the Christian community, the Pope, stood up with the sole force of his moral authority. The head of the Church, bishop of Rome, became the main point of reference of the city, assuming functions that were not only ritualistic, being the only force capable of mobilizing the necessary resources to support the population in times of difficulty. imperial Western, together with the not always effective, if not inappropriate, intervention of the Eastern emperor in the affairs of Rome, created a political vacuum which was occupied by the Pope. The action of the Church manifested itself along two lines: an effective economic and welfare structure aimed primarily at the weakest categories – the poor, the infirm, single women, orphaned children – but also for the benefit of the entire citizenry, in case of need, and of the increasingly numerous pilgrims from all over; promote a diplomatic action of mediation towards external forces – the Eastern Empire, the barbarian princes, then Christianized – to guarantee the security of Rome.The Roman nobility remained divided between those who supported the Pope and those who opposed his growing power . The author identifies the antecedents of this division in early Christianity, when a part of the Roman aristocrats fervently embraced the new faith, putting all their energies and heritage at the service of the Church, while another part remained jealous guardian of traditions. The most ambitious challenge was the conversion of the barbarian populations that occupied what were the western provinces of the Roman Empire. The leaders of these peoples ended up recognizing the moral authority of the Pope, considering the Church the heir to the civilizing tradition of Rome. The authority of the Church culminated with the coronation of Charlemagne, patricius Romanorum and prince of the Holy Roman Empire, which took place in St. Peter’s on Christmas day in the year 800. Since then, the Germanic princes sought the consecration of their power in Rome. , but between papacy and empire for centuries concord alternated with conflict. Rome remained at the center of the political attention of the West, but paid a very high price. The imperial armies threatened and attacked the city several times; the pope often abandoned Rome in the face of violence, of which the nobility and the people were protagonists, alongside the Pope or the emperor, and victims at the same time.The development of a commercial bourgeoisie led to the birth of the Municipality in the 12th century, in analogy with what happened in other Italian cities. The new institution attempted to carve out a space of autonomy in the administration of the city of Rome, by force of circumstances placing itself in opposition to the Pope. The balance of power therefore remained unstable, unlike other Italian cities, in which the of the comone asserted itself at the expense of the bishop. The special position of the bishop of Rome constituted an insurmountable obstacle for the municipal authorities, who over time were brought back to a position of subordination to the Pope. Following a development similar to other Italian realities, with the passage from the Middle Ages to the Renaissance, the Pope established himself as the lord of Rome and its territory. Like the lords of the other states of Italy, the Pope participated in the game of changing alliances, in which foreign sovereigns were called to join, in support of one or the other side. These external forces were much stronger than the local actors and pursued their own designs, not always compatible with those who had requested their intervention. The tragic culmination of this papal diplomacy was the sack of Rome in 1527. Pope Clement VII stubbornly opposed the emperor Charles V, provoking his reaction. The anti-papal nobility sided with the emperor, following a customary pattern. The consequences were very serious: the divisions between the city forces unguarded Rome in the face of the imperial threat. The defenses of the city were overwhelmed, Rome was subjected to a very hard and bloody looting. The population was decimated by violence, which was followed by famines and epidemics. No more than 30,000 citizens remained in the city. The sack of Rome ended an era, it was the last tragic episode that saw the papacy, the empire, the Roman nobility and the people as protagonists, the four forces that shaped the destiny of Rome in the Middle Ages. useful chronology, a ten-page index of names and almost fourteen pages of invaluable bibliography, commented and organized for centuries. Giampiero MarcelloFrom the advent of Constantine to the famous sack of Charles V in 1527: twelve hundred years of Rome’s history appear in this reconstruction carried out by Ludovico Gatto, a serious scholar of the medieval age. His detailed analysis of all the fundamental events of the time composes the pieces of a broad political, religious, economic, social, cultural, building, urbanistic framework, If it is true that the historiographic sources available to us in general on the medieval era there are not many, it must instead be recognized that there are more testimonies relating to the specific situation in Rome. Documentary and narrative evidence, not to mention the building and town planning vestiges. For works of historical literature, the most immediate reference is the History of the city of Rome in the Middle Ages by Ferdinando Gregorovius, built around the evaluation of two great fundamental elements: the great tradition of the universal Church and the equally great memory of the Roman Empire.