Question: Which comune is located in Latium, the city in Rome which grew to be the capital of the Roman Empire?

Context articles: Third Rome
Roman conquest of Italy
Paganico Sabino
Byzantine Empire
History of the Byzantine Empire
Rome
Ficana
Latium
Campagnano di Roma
Old Latium

Third Rome is the hypothetical successor to the legacy of ancient Rome (the "first Rome").
 Second Rome usually refers to Constantinople, the capital of the Byzantine Empire, officially called "New Rome", or one of the claimed successors to the Western Roman Empire such as the Papal States, the Holy Roman Empire, Moscow and the Italian Republic.
The Roman conquest of Italy was the result of a series of conflicts in which the city-state of Rome grew from being the dominant state in Latium to become the ruler of all of Italy.
 The first major Roman conquest in historical times came with the final defeat of her neighbour Veii in 396 BC.
 In the second half of the 4th century BC Rome clashed repeatedly with the Samnites, a powerful tribal coalition.
 By the end of these wars Rome had become the most powerful state in Italy.
 The last threat to Roman hegemony came when Tarentum enlisted the aid of Pyrrhus of Epirus during the Pyrrhic War (282 - 273 BC).
 By 218 BC Roman conquest of Italy had been completed.
 Conquered territories were incorporated into the growing Roman state in a number of ways: land confiscations, establishment of "coloniae", granting of full or partial Roman citizenship and military alliances with nominally independent states.
 The successful conquest of Italy gave Rome access to a manpower pool unrivalled by any contemporary state and led the way to the eventual Roman domination of the entire Mediterranean world.
Paganico Sabino is a "comune" (municipality) in the Province of Rieti in the Italian region Latium, located about 50 km northeast of Rome and about 25 km southeast of Rieti.
 As of 31 December 2004, it had a population of 196 and an area of 9.2 km2 .
The Byzantine Empire, also referred to as the Eastern Roman Empire, was the continuation of the Roman Empire in the East during Late Antiquity and the Middle Ages, when its capital city was Constantinople (modern-day Istanbul, which had been founded as Byzantium).
 It survived the fragmentation and fall of the Western Roman Empire in the 5th century AD and continued to exist for an additional thousand years until it fell to the Ottoman Turks in 1453.
 During most of its existence, the empire was the most powerful economic, cultural, and military force in Europe.
 Both "Byzantine Empire" and "Eastern Roman Empire" are historiographical terms created after the end of the realm; its citizens continued to refer to their empire as the "Roman Empire" (Greek: Βασιλεία τῶν Ῥωμαίων , tr.
 "Basileia tôn Rhōmaiōn" ; Latin: "Imperium Romanum" ), or "Romania" (Ῥωμανία ), and to themselves as "Romans".
This history of the Byzantine Empire covers the history of the Eastern Roman Empire from late antiquity until the Fall of Constantinople in 1453 AD.
 Several events from the 4th to 6th centuries mark the transitional period during which the Roman Empire's east and west divided.
 In 285, the emperor Diocletian (r. 284–305) partitioned the Roman Empire's administration into eastern and western halves.
 Between 324 and 330, Constantine I (r. 306–337) transferred the main capital from Rome to Byzantium, later known as "Constantinople" ("City of Constantine") and "Nova Roma" ("New Rome").
 Under Theodosius I (r. 379–395), Christianity became the Empire's official state religion and others such as Roman polytheism were proscribed.
 And finally, under the reign of Heraclius (r. 610–641), the Empire's military and administration were restructured and adopted Greek for official use instead of Latin.
 Thus, although it continued the Roman state and maintained Roman state traditions, modern historians distinguish Byzantium from ancient Rome insofar as it was oriented towards Greek rather than Latin culture, and characterised by Orthodox Christianity rather than Roman polytheism.
Rome ( ; Italian: "Roma" ] , Latin: "Rōma" ) is the capital of Italy and a special comune (named "Comune di Roma Capitale").
 Rome also serves as the capital of the Lazio region.
 With 2,877,215 residents in 1285 km2 , it is also the country's most populated comune.
 It is the fourth-most populous city in the European Union by population within city limits.
 It is the center of the Metropolitan City of Rome, which has a population of 4.3 million residents.
 Rome is located in the central-western portion of the Italian Peninsula, within Lazio (Latium), along the shores of the Tiber.
 The Vatican City is an independent country inside the city boundaries of Rome, the only existing example of a country within a city: for this reason Rome has been often defined as capital of two states.
Ficana was an ancient city of Latium, which figures in Roman history only on the occasion of its conquest by Ancus Marcius, who is said to have removed the inhabitants to Rome, and destroyed the city itself.
 (Livy i. 33; Dionys.
 iii.
 38, where the editions have "Fidenae", but there is little doubt that the event referred to is the same related by Livy.)
 It is certain that it was never repeopled: its name is found in Pliny's list of the extinct cities of Latium (iii.
 5.
 s. 9), and is noticed also by Festus ("v. Puilia Saxa") as a place no longer in existence.
 The latter passage, however, affords us a clue to its position; according to Marcus Antistius Labeo there cited, it was situated on the Via Ostiensis, eleven miles from Rome, and apparently immediately adjoining the Tiber, on which it had a port, at a place called by Fabius Pictor the "Puilia Saxa".
 The city's site is in the commune of Rome near Acilia, on the via Ostiense between Rome and Ostia.
Latium (Latin: "Lătĭŭm" ] ) is the region of central western Italy in which the city of Rome was founded and grew to be the capital city of the Roman Empire.
 Latium was originally a small triangle of fertile, volcanic soil on which resided the tribe of the Latins or Latians.
 It was located on the left bank (east and south) of the River Tiber, extending northward to the River Anio (a left-bank tributary of the Tiber) and southeastward to the Pomptina Palus (Pontine Marshes, now the Pontine Fields) as far south as the Circeian promontory.
 The right bank of the Tiber was occupied by the Etruscan city of Veii, and the other borders were occupied by Italic tribes.
 Subsequently, Rome defeated Veii and then its Italic neighbours, expanding Latium to the Apennine Mountains in the northeast and to the opposite end of the marsh in the southeast.
 The modern descendant, the Italian "Regione" of Lazio, also called "Latium" in Latin, and occasionally in modern English, is somewhat larger still, but not as much as double the original Latium.
Campagnano di Roma is a "comune" (municipality) in the Metropolitan City of Rome in the Italian region Latium, located about 30 km northwest of Rome.
 It was first mentioned in 1076, having been carved out of the great estate assembled on the Roman pattern by Pope Adrian I, ca. 780, his "Domusculta Capracorum".
 In medieval times, Campagnano di Roma was on the "via Francigena".
 Here, Sigeric, Archbishop of Canterbury, sojourned on his return journey from Rome about 990.
Old Latium (Latin: "Latium vetus" or "Latium antiquum ") is a region of the Italian peninsula bounded to the north by the river Tiber, to the east by the central Apennine mountains, to the west by the Mediterranean Sea and to the south by Monte Circeo.
 It was the territory of the Latins, an Italic tribe which included the early inhabitants of the city of Rome.
 Later it was also settled by various Italic tribes such as the Rutulians, Volscians, Aequi, and Hernici.
 The region was referred to as "old" to distinguish it from the expanded region, Latium, that included the region to the south of Old Latium, between Monte Circeo and the river Garigliano - the so-called Latium adiectum ("attached Latium").
 It corresponded to the central part of the modern administrative region of Lazio, Italy, and it covered an area measuring of roughly 50 Roman miles.
 It was calculated by Mommsen that the region's area was about 1860 square kilometres.