Roman Kingdom in the context of "Roman Republic"

In modern historiography, ancient Rome is the Roman civilisation from the founding of the Italian city of Rome in the 8th century BC to the collapse of the Western Roman Empire in the 5th century AD. It encompasses the Roman Kingdom (753–509 BC), the Roman Republic (509‍–‍27 BC), and the Roman Empire (27 BC – 476 AD) until the fall of the western empire.

Ancient Rome began as an Italic settlement, traditionally dated to 753 BC, beside the River Tiber in the Italian Peninsula. The settlement grew into the city and polity of Rome, and came to control its neighbours through a combination of treaties and military strength. It eventually controlled the Italian Peninsula, assimilating the Greek culture of southern Italy (Magna Graecia) and the Etruscan culture, and then became the dominant power in the Mediterranean region and parts of Europe. At its height it controlled the North African coast, Egypt, Southern Europe, and most of Western Europe, the Balkans, Crimea, and much of the Middle East, including Anatolia, the Levant, and parts of Mesopotamia and Arabia. That empire was among the largest empires in the ancient world, covering around 5 million square kilometres (1.9 million square miles) in AD 117, with an estimated 50 to 90 million inhabitants, roughly 20% of the world's population at the time. The Roman state evolved from an elective monarchy to a classical republic and then to an increasingly autocratic military dictatorship during the Empire.

The Roman people was the ethnicity and the body of Roman citizens(Latin: Rōmānī; Ancient Greek: Ῥωμαῖοι Rhōmaîoi) during the Roman Kingdom, the Roman Republic, and the Roman Empire. This concept underwent considerable changes throughout the long history of the Roman civilisation, as its borders expanded and contracted. Originally only including the ethnic Latins from Rome itself, Roman citizenship was extended to the rest of the Italic peoples by the 1st century BC and to nearly every subject of the Roman empire in late antiquity. At their peak, the Romans ruled large parts of Europe, the Near East, and North Africa through conquests made during the Roman Republic and the subsequent Roman Empire. Although defined primarily as a citizenship, "Roman-ness" has also and variously been described as a cultural identity, a nationality, or a multi-ethnicity that eventually encompassed a vast regional diversity.

Citizenship grants, demographic growth, and settler and military colonies rapidly increased the number of Roman citizens. The increase achieved its peak with Emperor Caracalla's AD 212 Antonine Constitution, which extended citizenship rights to all free inhabitants of the empire. Roman identity provided a larger sense of common identity and became important when distinguishing from non-Romans, such as barbarian settlers and invaders. Roman culture was far from homogeneous; though there was a common cultural idiom, one of the strengths of the Roman Empire was also its ability to incorporate traditions from other cultures, notably but not exclusively Greece.

Rome is the capital city and most populated comune (municipality) of Italy. It is also the administrative centre of the Lazio region and of the Metropolitan City of Rome. A special comune named Roma Capitale with 2,746,984 residents in 1,287.36 km (497.1 sq mi), Rome is the third most populous city in the European Union by population within city limits. The Metropolitan City of Rome Capital, with a population of 4,223,885 residents, is the most populous metropolitan city in Italy. Its metropolitan area is the third-most populous within Italy. Rome is located in the central-western portion of the Italian Peninsula, within Lazio (Latium), along the shores of the Tiber Valley. Vatican City (the smallest country in the world and headquarters of the worldwide Catholic Church under the governance of the Holy See) is an independent country inside the city boundaries of Rome, the only existing example of a country within a city. Rome is often referred to as the City of Seven Hills due to its geography, and also as the "Eternal City". Rome is generally considered to be one of the cradles of Western civilization and Western Christian culture, and the centre of the Catholic Church.

Rome's history spans 28 centuries. While Roman mythology dates the founding of Rome at around 753 BC, the site has been inhabited for much longer, making it a major human settlement for over three millennia and one of the oldest continuously occupied cities in Europe. The city's early population originated from a mix of Latins, Etruscans, and Sabines. Eventually, the city successively became the capital of the Roman Kingdom, the Roman Republic and the Roman Empire, and is regarded by many as the first-ever Imperial city and metropolis. It was first called The Eternal City (Latin: Urbs Aeterna; Italian: La Città Eterna) by the Roman poet Tibullus in the 1st century BC, and the expression was also taken up by Ovid, Virgil, and Livy. Rome is also called Caput Mundi (Capital of the World).

Roman Italy is the period of ancient Italian history going from the founding and rise of Rome to the decline and fall of the Western Roman Empire; the Latin name of the Italian peninsula in this period was Italia (continued to be used in the Italian language). According to Roman mythology, Italy was the ancestral home of Aeneas, being the homeland of the Trojans progenitor, Dardanus; Aeneas, instructed by Jupiter, moved to Italy after the fall of Troy, and his descendants, Romulus and Remus, were the founders of Rome. Aside from the legendary accounts, Rome was an Italic city-state that changed its form of government from Kingdom (ruled, between 753 BC and 509 BC, by seven kings) to Republic, and then grew within the context of a peninsula dominated by the Gauls, Ligures, Veneti, Camunni and Histri in the North; the Etruscans, Latins, Falisci, Picentes, Umbri and Sabines in the Centre; and the Iapygian tribes (such as the Messapians), the Oscan tribes (such as the Samnites) and Greek colonies in the South.

The consolidation of Italy into a single entity occurred during the Roman expansion in the peninsula, when Rome formed a permanent association with most of other the local tribes and cities; and Italy's inhabitants included Roman citizens, communities with Latin Rights, and socii. The strength of the Italian confederacy was a crucial factor in the rise of Rome, starting with the Punic and Macedonian wars between the 3rd and 2nd century BC. As Roman provinces were being established throughout the Mediterranean, Italy maintained a special status with political, religious and financial privileges. In Italy, Roman magistrates exercised the imperium domi (police power), as an alternative to the imperium militiae (military power) exercised in the provinces.

The Roman deities most widely known today are those the Romans identified with Greek counterparts, integrating Greek myths, iconography, and sometimes religious practices into Roman culture, including Latin literature, Roman art, and religious life as it was experienced throughout the Roman Empire. Many of the Romans' own gods remain obscure, known only by name and sometimes function, through inscriptions and texts that are often fragmentary. This is particularly true of those gods belonging to the archaic religion of the Romans dating back to the era of kings, the so-called "religion of Numa", which was perpetuated or revived over the centuries. Some archaic deities have Italic or Etruscan counterparts, as identified both by ancient sources and by modern scholars. Throughout the Empire, the deities of peoples in the provinces were given new theological interpretations in light of functions or attributes they shared with Roman deities.

A survey of theological groups as constructed by the Romans themselves is followed by an extensive alphabetical list concluding with examples of common epithets shared by multiple divinities.

The Roman Senate (Latin: Senātus Rōmānus) was the highest and constituting assembly of ancient Rome and its aristocracy. With different powers throughout its existence, it lasted from the first days of the city of Rome (traditionally founded in 753 BC) as the Senate of the Roman Kingdom, to the Senate of the Roman Republic and Senate of the Roman Empire and eventually the Byzantine Senate of the Eastern Roman Empire, existing well into the post-classical era and Middle Ages.

During the days of the Roman Kingdom, the Senate was generally little more than an advisory council to the king. However, as Rome was an electoral monarchy, the Senate also elected new Roman kings. The last king of Rome, Lucius Tarquinius Superbus, was overthrown following a coup d'état led by Lucius Junius Brutus, who founded the Roman Republic. During the early Republic, the Senate was politically weak, while the various executive Roman magistrates who appointed the senators for life (or until expulsion by Roman censors) were quite powerful. Since the transition from monarchy to constitutional rule was most likely gradual, it took several generations before the Senate was able to assert itself over the executive magistrates. By the middle Republic, the Senate had reached the apex of its republican power. The late Republic saw a decline in the Senate's power, which began following the reforms of the tribunes Tiberius and Gaius Gracchus. After the transition of the Republic into the Principate, the Senate lost much of its political power as well as its prestige.