The name Rome comes from Latin Roma, and its origin is uncertain. Roman tradition said the city was named after its founder Romulus, but most modern scholars think the reverse: the legendary Romulus was named after a city that already existed. Linguists have proposed three main sources for Roma itself: Rumon or Rumen, an archaic name for the Tiber linked to a root meaning "to flow"; an Etruscan word ruma (𐌓𐌖𐌌𐌀); and the Greek rhṓmē (ῥώμη), "strength". None is proven. The name itself has never changed, but the formal names of the state and the municipality built around it have changed many times, from a kingdom in the 8th century BC to Roma Capitale today.
Rumon, ruma or rhōmē: three roots proposed for Roma
Alternative theories about the name are not modern. Rival explanations were already being proposed as early as the 4th century, and the three surviving candidates each have something to recommend them. The first takes Roma from Rumon or Rumen, said to be an archaic name of the Tiber, related to the Greek verb rhéō (ῥέω), "to flow, stream", and the Latin ruō, "to hurry, rush". On this view Rome would be "the river town", named after the water that made the site a crossing point.
The second points to Etruscan, the language of Rome's neighbours to the north. The Etruscan word ruma is built on a root *rum-, "teat". Supporters connect it either to the she-wolf who in legend suckled the twins Romulus and Remus, or to the rounded shape of the Palatine and Aventine hills. The third theory, Greek rhṓmē, "strength", has the appeal of a flattering meaning. Specialist surveys treat all three as possibilities whose linguistic roots remain uncertain. The guide to the Tiber describes the river behind the first theory.
21 April 753 BC: Roma and the Romulus legend
The oldest official date in Rome's naming is a legendary one. According to the Roman annalists, Romulus founded the city on 21 April 753 BC, after killing his twin Remus in a quarrel over where it should stand, and named it after himself. The canonical versions are those of Livy, Dionysius of Halicarnassus and Plutarch, all writing centuries later. Roman historians themselves placed the foundation anywhere between 758 and 728 BC, and Plutarch reports a calculation by Tarutius, a friend of the scholar Varro, that the twins were born in 771 BC.
The legend's most visible symbol has its own dating problem. The bronze Capitoline Wolf was long thought to be an Etruscan work of the 5th century BC, with the twins added in the late 15th century AD, probably by Antonio del Pollaiuolo. Radiocarbon and thermoluminescence tests in the 21st century suggested the wolf may instead have been cast between 1021 and 1153, though those results are contested. Archaeology is similarly cautious about the founding itself: the site was inhabited long before 753 BC, and the idea that Rome was founded deliberately in the mid-8th century, as the Romulus story implies, remains a fringe hypothesis. The legend explains the name after the fact rather than recording its birth.
509 BC to 80 BC: from ROMA to Senatus Populusque Romanus
The first great change in how the Roman state named itself began with the end of the monarchy, though it took centuries to settle. In 509 BC the Romans expelled their last king and set up a republic led by two consuls elected each year. At first the official name of the state, as its coins show, was simply ROMA. Only in the Late Republic, from around 80 BC, does the formula Senatus Populusque Romanus, "the Senate and People of Rome", abbreviated SPQR, appear in inscriptions; it went on to mark dedications of monuments and public works and, until Constantine the Great, coins, and it runs through the speeches of Cicero and Livy's history Ab Urbe Condita, "from the founding of the city".
The census recorded a population of 130,000 when the Republic was founded, counting the city and its immediate surroundings, and Rome passed 300,000 by 150 BC. SPQR outlived the Republic by many centuries: it is still in the municipal coat of arms of Rome and serves as an abbreviation for the comune in official documents. From 1184 the medieval Commune of Rome struck coins in the name of the SENATVS P Q R, so the formula bridged the ancient and papal cities.
27 BC to AD 476: Urbs Aeterna and Caput Mundi
In 27 BC Octavian took the name Augustus and the title princeps, creating the system historians call the Principate, and Rome became the capital of an empire. Its titles grew to match. The poet Tibullus first called it Urbs Aeterna, "the Eternal City", in the 1st century BC, and the expression was taken up by Ovid, Virgil and Livy. The city was also Caput Mundi, "capital of the world", and often simply Urbs, "the city", with no further explanation needed.
Population estimates for the Augustan city range widely, from Glenn Storey's 450,000 to Whitney Oates's 1.2 million. The western empire ended on 4 September 476, when Romulus Augustus, who lived at Ravenna rather than Rome, was deposed. By then emperors had long governed from elsewhere, and Constantine's eastern capital was being called "New Rome", so the city's name had become a prestige label that other cities borrowed.
756: the Donation of Pepin and the Papal States
After 476 Rome passed to Odoacer, then to the Ostrogothic Kingdom, and back to East Roman control after the Gothic War, which devastated the city in 546 and 550. By the 8th century the city and its hinterland formed the Duchy of Rome. In 756 the Frankish king Pepin the Short, having defeated the Lombards, gave the Pope temporal jurisdiction over the Duchy of Rome and the Exarchate of Ravenna. That grant, the Donation of Pepin, created the Papal States, and Rome was their capital for more than eleven centuries, until 1870.
Under the popes Rome added new titles: the Throne of St Peter, and in time the seat of a sovereign church state. When the Lateran Treaty of 1929 created Vatican City as a separate state, it was carved out of the city of Rome, so the old papal capital and the smallest state in the world now share one urban area.
1798 to 1849: Repubblica Romana, Tibre and the Département de Rome
Revolutionary France gave Rome three new formal names in twelve years. The French general Louis-Alexandre Berthier occupied the city on 11 February 1798, and on 15 February the Roman Republic (Repubblica Romana) was proclaimed as a sister republic of the First French Republic, governed by a Directory of five men. Neapolitan troops restored papal rule in October 1799, and the Papal States were formally re-established in June 1800.
Napoleon then annexed the city outright. On 17 May 1809, when most of the Papal States were absorbed into the French Empire, Rome became the capital of a department named Tibre, after the Tiber. On 17 February 1810 the department was renamed Rome, and Napoleon granted his son, Napoleon II, the title King of Rome. After Napoleon's defeat the Congress of Vienna restored the Papal States to Pius VII in 1814. A second Roman Republic followed on 9 February 1849, after Pope Pius IX had fled to Gaeta in November 1848; it was led by a triumvirate of Carlo Armellini, Giuseppe Mazzini and Aurelio Saffi, deliberately echoing ancient Roman government, and its constitution guaranteed freedom of religion. In April 1849 Louis Napoleon sent French troops under General Charles Oudinot to restore the Pope, and French forces were still protecting the last of his territory in the 1860s.
20 September 1870: Roma, capital of Italy
When the Kingdom of Italy was proclaimed on 17 March 1861 it did not include Rome, which remained papal under French protection. The capital moved from Turin to Florence while the question stayed open. In 1870 the outbreak of the Franco-Prussian War forced France to withdraw its garrison, and on 20 September 1870 the Italian army breached the Aurelian Walls near Porta Pia and entered the city. After a plebiscite on 2 October 1870, Rome was officially made capital of Italy on 3 February 1871, ending the Papal States and the temporal power of the Holy See.
The date became a place name in its own right: streets across Italy, especially in cathedral cities, are called Via XX Settembre. In 1870 the city had about 212,000 people, all living within the ancient walls; by 1920 it had 660,000. In 1946 the Kingdom of Italy became the Italian Republic, and Rome remained its capital, as it is today.
Roma Capitale and the Metropolitan City, 2015
The most recent change is administrative. The municipality is now a comune speciale with the formal name Roma Capitale, with about 2.7 million people in an area of 1,287.36 km², the largest of Italy's 8,101 comuni by both land area and population. On 1 January 2015, under Law 56/2014, the old Province of Rome was replaced by the Metropolitan City of Rome Capital (Città metropolitana di Roma Capitale), which covers the city and 120 other comuni, nearly a third of the Lazio region, and had 4,224,901 residents as of 2026, the largest metropolitan city in Italy. Its metropolitan mayor is the mayor of Rome, Roberto Gualtieri, in office since 21 October 2021.
So the word Roma has outlasted a monarchy, a republic, an empire, the Papal States, two short-lived republics and a French department, while its meaning stays out of reach. For today's city, see our guide to Rome, capital of Italy, and for the city that once called itself New Rome and changed its own name far more often, read how Istanbul got its name.