According to legend, the city of Rome was founded in 753 BCE by Romulus, a descendant of Troy, after he murdered his twin brother, Remus. The city was a union of villages based upon the Seven Hills of Rome by the River Tiber, of which the Palatine Hill served as the city center.
In the 6th century BCE, King Servius Tullius expanded Rome and organized it into four administrative regions, or quarters.
In 509 BCE, the Roman Senate overthrew King Lucius Tarquinius Superbus due to his despotic ways and established the Roman Republic. Rome continued to serve as the capital of this new republic and the center of the vast territories it would soon acquire.
The Romans were an Italic people who spoke Latin. Their neighbors included other Italic peoples such as non-Roman Latins and the Sabines, and the mysterious Estruscans.
In 387 BCE, Rome was sacked by the Senones, a tribe of the Celtic Gauls. After surviving this incident, Rome began to expand aggressively, subduing Celts, Latins, and Etruscans alike. By the end of the 4th century BCE, Rome had brought much of the Italian Peninsula under its control.
Shortly after the Senone raid, the Servian Wall was built to fortify Rome, including all seven hills. However, the pomerium, which was the religious and official boundary of the city, remained limited to the Palatine Hill. The pomerium was a strictly civilian space, banning generals and weapons alike.
As Rome expanded, it built a network of paved roads throughout its conquered territories. The roads facilitated the transportation of people, trade goods, communications, and, of course, armies. The paths of some of these roads, such as the Via Tiburtina and the Via Aurelia, are preserved by modern highways.
Rome began to expand beyond Italy and throughout the Mediterranean in the 2nd century BCE. By 146 BCE, it had conquered both Greece and Carthage, in modern-day Tunisia. Its territory stretching from Spain in the west to Turkey in the east, Rome was soon the hegemon of the Mediterranean world.
In the early 1st century BCE, the Roman general Sulla launched a coup and brought an army into the pomerium for the first time in Roman history. He revived the old office of dictator, granting him vast emergency powers. This allowed him to rewrite the constitution and expand the pomerium beyond Palatina.
Though Sulla intended to save the republic by strengthening the Senate and weakening the tribunes, who were elected officials whose powers often superseded those of the Senate. However, his reforms did not last, and had the unintended consequence of setting a precedent for future military coups.
Just one generation later, Julius Caesar seized control of Rome. As dictator for life, Caesar implemented reforms such as centralizing the government and expanding the citizenship program. He was eventually assassinated by the political elite, but his son Octavian would carry on his legacy.
After winning a civil war, Octavian abolished the republic and established the Roman Empire, becoming Augustus. He reorganized the city of Rome into the Fourteen Regions, replacing the four quarters that had existed since the Roman Kingdom. During this period, Rome exceeded one million in population.
Rome survived a major test in 64 CE when two-thirds of the city was destroyed by the Great Fire of Rome. Traditional accounts suggest that Emperor Nero blamed the fire on Christianity, a new religion at this time. Though the fire was devastating, it provided a clean slate for new urban planning.
From the beginning of the empire in 27 BCE to the death of Emperor Marcus Aurelius in 180 CE, Rome experienced a golden age known as Pax Romana, or “Roman Peace.” Though rebellions and wars continued during this period, the Pax Romana was, relatively speaking, a time of unprecedented stability.
Rome’s golden age came to an end in the late 2nd century. First, the Antonine Plague, brought back from the eastern city of Seleucia by Roman troops, killed thousands. The Crisis of the Third Century, a decades-long culmination of civil wars, rebellions, and Germanic invasions, nearly destroyed the empire.
Upon reuniting the empire, Aurelian further fortified Rome with the Aurelian Walls in 275. Despite the new fortification, Rome was no longer the favored residence of the emperors. Though it remained the de jure capital, Rome was replaced by cities such as Mediolanum (Milan), Ravenna, and Nicomedia.
Though its politial prowess was fast declining, Rome gained newfound religious significance when the empire to Christianity in the 4th century. In 380, the Edict of Thessalonica elevated the Bishop of Rome as the senior Christian figure of the empire, marking the beginning of the modern papacy.
In 395, the empire was permanently split into Western and Eastern halves, though the division had existed under the system of Tetrarchy since the end of the Crisis of the Third Century. Rome remained the de jure capital of the Western half, and was constantly threatened by Germanic invaders throughout the 400s.
In 410, Rome was sacked for the first time since 387 BCE by the Germanic Visigoths. After a series of sackings, Rome fell to the Germanic warlord Odoacer in 476. This ended the Western empire. Odoacer’s Kingdom of Italy, nominally a vassal of the Eastern Romans, was based in Ravenna rather than Rome.
Odoacer was defeated by Theodoric the Great, king of the Ostrogoths, in 493. The Ostrogothic Kingdom also set its capital in Ravenna, and Rome’s population dipped well below 100,000. Yet Gothic rule of Rome was short lived; in 536, the Eastern Romans (or Byzantines) under Justinian recaptured Rome.
The Goths resisted Byzantine rule, leading to the Gothic War of 535-554. The war devastated the population of Rome, bringing it down to 30,000 at its lowest. After defeating the Goths, Justinian attempted to restore Rome to its former glory by funding infrastructure projects and education.
Still, Rome remained politically subservient to Ravenna, the seat of the Byzantine administration in Italy. The Byzantine officials overwhelmed the authority of the Roman Senate, which had survived as a local government body. The greater threat to Byzantine authority was the pope.
By the 8th century, the papacy had turned on the Byzantines. When the Germanic Lombards, allied with the Byzantines, threatened to take Rome, Pope Stephen II appealed to the Germanic Franks for help. They defeated the Lombards together, and the Franks gave the pope his own Papal States in 756.
With the Byzantines gone, local noble families became the papacy’s chief political rivals. In 799, Pope Leo III sought refuge in Francia after two nobles attempted to depose him. Charlemagne, king of the Franks, restored Leo, and he crowned Charlemagne Holy Roman Emperor on Christmas Day, 800.
This act severed all ties between the Papal States and the Byzantines. However, when Charlemagne died in 814, his empire declined and the pope was left without a powerful ally. The pope laid claim to much of Italy through the fabricated Donation of Constantine, but local nobles were really in control.
In the 10th century, a group of nobles known as the Counts of Tusculum took political control of Rome, including the selection of popes. The period between 904 and 964 is known as the saeculum obscurum, or “the dark age.” In 962, Otto I restored the Holy Roman Empire and installed a puppet pope for a time.
Meanwhile, the old Fourteen Regions of Rome that were established by Augustus had long fallen into disuse. Eventually, a new set of administrative divisions known as the Twelve Regions emerged. In 852, Pope Leo IV built the Leonine Wall in the northwest, annexing what is now Vatican City to Rome.
In 1052, the religious East-West Schism permanently split the Roman Catholic Church from the Byzantines’ Eastern Orthodox Church. Meanwhile, the pope and the Holy Roman emperor also fought over the right to appoint bishops through the Investiture Controversy, which began in 1076.
The controversy was resolved in 1122 with the Concordat of Worms; the pope would continue to appoint bishops, but the bishops would also have to swear loyalty to their secular ruler. In 1177, the Holy Roman Empire forfeited all claims to the city of Rome in the Treaty of Venice, securing the pope’s control.
By the 12th century, the merchant and banking class were supplanting the landed nobility throughout Italy. In 1143, Giordano Pierleoni, a member of this new middle class, overthrew the government and established the Commune of Rome. Rome was reorganized into the Fourteen Regions.
The Commune of Rome collapsed in 1193 and the Papal States were restored. The 13th century saw a reignition of the conflict between the Papal States and the Holy Roman Empire; the Guelph faction of nobles supported the pope, while the Ghibelline faction supported the empire.
This Guelph-Ghibelline conflict raged on across all of Italy until the end of the 1300s. For much of that century, the papacy was absent from Rome; from 1309 to 1378, the pope resided in the now-French city of Avignon, starting with the French Pope Clement V. This period is dubbed the Avignon Papacy.
The pope returned to Rome in 1378, but a line of Avignon popes continued to claim legitimacy, leading to the Western Schism. Adding a third pope in Pisa in 1409 only worsened matters; the conflict finally ended in 1429 when all three popes were deposed and replaced by a single Roman pope.
With the papacy reunified and the Holy Roman Empire expelled from Italy, Rome finally found peace in the 15th century. The Italian Renaissance, which had begun in Florence in the 14th century, shifted its center to Rome in the mid-15th. The Roman Renaissance was aided by a massive papal budget.
Famous artists such as Michelangelo and Raphael produced iconic artworks like the Sistine Chapel. Grand religious ceremonies such as jubilees and Carnivals attracted pilgrims, and Rome’s population began to grow again. By the end of the century, the pope had grown politically powerful and corrupt.
However, the papacy’s geopolitical ambitions were crushed in 1527 when the armies of Charles V, Holy Roman Emperor, decimated Rome. At the same time, the Protestant Reformation, the English Reformation, and the rise of the Muslim Ottoman Empire were all threatening papal authority.
For the latter half of the 16th century, the papacy focused on the Counter-Reformation, a series of political and religious reforms meant to defend Catholicism against Protestantism and other threats. Pope Sixtus V (1585-1590) attempted to root out corruption and implement stricter religious law.
In 1643, Pope Urban VIII oversaw the construction of the Janiculum walls, which expanded upon the old Leonine wall of the northwest. With this, the borders of the modern city center of Rome was mostly completed. Furthermore, by this time, the medieval regions of Rome had evolved into rioni.
By the 18th century, Rome had recovered the strength it had enjoyed during the Renaissance. It once again flourished as a center of the arts, especially the Baroque and Roccoco styles.
In the late 18th and early 19th centuries, Rome was ruled by the Revolutionary French-aligned Roman Republic, then by Napoleonic France. After Napoleon’s defeat, the Papal States became staunchly reactionary.
Italian unification soon began. Rome was captured by the new Kingdom of Italy in 1870 and made its capital the following year; the pope was reduced to a prisoner in the Vatican. The Lateran Treaty of 1929 eventually established Vatican City as a sovereign state ruled by the pope.