Imperium in the context of "Privatus"

During the classical period, the Roman Empire controlled the Mediterranean and much of Europe, Western Asia, and North Africa. The Romans conquered most of these territories in the time of the Republic, and it was ruled by emperors following Octavian's assumption of power in 27 BC. Over the 4th century AD, the empire split into western and eastern halves. The western empire collapsed in 476 AD, while the eastern empire endured until the fall of Constantinople in 1453.

By 100 BC, the city of Rome had expanded its rule from the Italian peninsula to most of the Mediterranean and beyond. However, it was severely destabilised by civil wars and political conflicts, which culminated in the victory of Octavian over Mark Antony and Cleopatra at the Battle of Actium in 31 BC, and the subsequent conquest of the Ptolemaic Kingdom in Egypt. In 27 BC, the Roman Senate granted Octavian overarching military power (imperium) and the new title of Augustus, marking his accession as the first Roman emperor. The vast Roman territories were organized into senatorial provinces, governed by proconsuls who were appointed by lot annually, and imperial provinces, which belonged to the emperor but were governed by legates.

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 consuls were the two highest elected public officials of the Roman Republic (c. 509 BC to 27 BC). Romans considered the consulship the second-highest level of the cursus honorum—an ascending sequence of public offices to which politicians aspired—after that of the censor, which was reserved for former consuls. Each year, the centuriate assembly elected two consuls to serve jointly for a one-year term. The consuls alternated each month holding fasces (taking turns leading) when both were in Rome. A consul's imperium (military power) extended over Rome and all its provinces.

Having two consuls created a check on the power of any one individual, in accordance with the republican belief that the powers of the former kings of Rome should be spread out into multiple offices. To that end, each consul could veto the actions of the other consul.

An empire is a realm controlled by an emperor or an empress and divided between a dominant center and subordinate peripheries. The center of the empire (sometimes referred to as the metropole) has political control over the peripheries. Within an empire, different populations may have different sets of rights and may be governed differently. The word "empire" derives from the Roman concept of imperium. Narrowly defined, an empire is a sovereign state whose head of state uses the title of "emperor" or "empress"; but not all states with aggregate territory under the rule of supreme authorities are called "empires" or are ruled by an emperor; nor have all self-described empires been accepted as such by contemporaries and historians (the Central African Empire of 1976 to 1979, and some Anglo-Saxon kingdoms in early England being examples).

There have been "ancient and modern, centralized and decentralized, ultra-brutal and relatively benign" empires. An important distinction has been between land empires made up solely of contiguous territories, such as the Achaemenid Empire, Roman Empire, the Mongol Empire, or the Russian Empire; and those - based on sea-power - which include territories that are remote from the 'home' country of the empire, such as the Dutch colonial empire, the Empire of Japan, the Chola Empire or the British Empire.

During the Roman Empire, the governor of Roman Egypt (praefectus Aegypti) was a prefect who administered the Roman province of Egypt with the delegated authority (imperium) of the emperor.

Egypt was established as a Roman province in consequence of the Battle of Actium, where Cleopatra as the last independent ruler of Egypt and her Roman ally Mark Antony were defeated by Octavian, the adopted heir of the assassinated Roman dictator Julius Caesar. Octavian then rose to supreme power with the title Augustus, ending the era of the Roman Republic and installing himself as princeps, the so-called "leading citizen" of Rome who in fact acted as an autocratic ruler. Although senators continued to serve as governors of most other provinces (the senatorial provinces), especially those annexed under the Republic, the role of Egypt during the civil war with Antony and its strategic and economic importance prompted Augustus to ensure that no rival could secure Aegyptus as an asset. He thus established Egypt as an imperial province, to be governed by a prefect he appointed from men of the equestrian order.

The Constitution of the Roman Empire was an unwritten set of guidelines and principles passed down mainly through precedent. After the fall of the Roman Republic, the constitutional balance of power shifted from the Roman Senate to the Roman Emperor. Beginning with the first emperor, Augustus, the emperor and the Senate were theoretically two co-equal branches of government. In practice, however, the actual authority of the imperial Senate was negligible, as the emperor held the true power of the state. During the reign of the second emperor, Tiberius, many of the powers that had been held by the Roman assemblies were transferred to the Senate.

The powers of an emperor existed by virtue of his legal standing. The two most significant components to an emperor's power were the "tribunician powers" Latin: tribunicia potestas and the proconsular imperium, or the power to command. The tribunician powers gave the emperor authority over Rome itself and the civil government, while the proconsular powers gave him authority over the provinces and the army. While these distinctions were clearly defined during the early empire, eventually they were lost, and the emperor's powers became less constitutional and more monarchical. The traditional magistracies that survived the fall of the Republic were the Consulship, Praetorship, Plebeian Tribunate, Aedileship, Quaestorship, and Military Tribunate. Any individual of the senatorial class could run for one of these offices. If an individual was not of the senatorial class, he could run for one of these offices if he was allowed to run by the emperor, or otherwise, he could be appointed to one of these offices by the emperor.