A ravaged Rome entered the Middle Ages with its once-proud population scattered and unrecognizable in rustic exile. A modest population started life again in the swamps of the Campus Martius, while the seven hills, now without water since the aqueducts were cut, stood abandoned and crumbling.
After the fall of the Western Empire, the pope took on more imperial powers, yet there was no political unity. Decades of rule by barbarians and then Goths were followed by takeovers in different parts of the country by various strong warriors, such as the Lombards. Italy was thus divided into several spheres of control. In 731, Pope Gregory II renounced Rome's dependence on Constantinople and thus ended the twilight era of the Greek exarch who had nominally ruled Rome.
Papal Rome turned toward Europe, where the papacy found a powerful ally in Charlemagne, a king of the barbarian Franks. In 800, he was crowned emperor by Pope Leo III. The capital he established at Aachen (Aix-la-Chapelle in French) lay deep within territory known to the Romans a half millennium ago as the heart of the barbarian world. Though Charlemagne pledged allegiance to the church and looked to Rome and its pope as the final arbiter in most religious and cultural affairs, he launched northwestern Europe on a course toward bitter political opposition to the meddling of the papacy in temporal affairs.
The successor to Charlemagne's empire was a political entity known as the Holy Roman Empire (962-1806). The new empire defined the end of the Dark Ages but ushered in a period of long, bloody warfare. The Lombard leaders battled Franks. Magyars from Hungary invaded northeastern Lombardy and were defeated, in turn, by the increasingly powerful Venetians. Normans gained military control of Sicily in the 11th century, divided it from the rest of Italy, and altered forever the island's racial and ethnic makeup and its architecture. As Italy dissolved into a fragmented collection of city-states, the papacy fell under the power of Rome's feudal landowners. Eventually, even the process for choosing popes came into the hands of the increasingly Germanic Holy Roman emperors, although this power balance would very soon shift.
Rome during the Middle Ages was a quaint rural town. Narrow lanes with overhanging buildings filled many areas that had once been showcases of ancient imperial power, such as the Campus Martius. The forums, mercantile exchanges, temples, and theaters of the Imperial Era slowly disintegrated and collapsed. The decay of ancient Rome was assisted by periodic earthquakes, centuries of neglect, and, in particular, the growing need for building materials. Rome receded into a dusty provincialism. As the seat of the Roman Catholic church, the state was almost completely controlled by priests, who had an insatiable need for new churches and convents.
By the end of the 11th century, the popes shook off control of the Roman aristocracy, rid themselves of what they considered the excessive influence of the emperors at Aachen, and began an aggressive expansion of church influence and acquisitions. The deliberate organization of the church into a format modeled on the hierarchies of the ancient Roman Empire put it on a collision course with the Holy Roman Empire and the other temporal leaders of Europe, resulting in an endless series of power struggles.
