''Consortium imperii'' is a

Latin Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...

term dating from the Roman

Dominate The Dominate is a periodisation of the Roman Empire during late antiquity Late antiquity marks the period that comes after the end of classical antiquity and stretches into the onset of the Early Middle Ages. Late antiquity as a period was p ...

, denoting the sharing of imperial authority between two or more

emperors The word ''emperor'' (from , via ) can mean the male ruler of an empire. ''Empress'', the female equivalent, may indicate an emperor's wife ( empress consort), mother/grandmother (empress dowager/ grand empress dowager), or a woman who rule ...

, each hence designated as ''consors imperii'', i.e., "partner in (exercising) ''imperium''", either as formal equals or in subordination, in which case the junior was often the senior's designated heir—not necessarily the natural one—and successor. In theory, this arrangement served to share the burden of government and ensure smooth succession, as rivalry at these moments was a major threat to the stability of the Empire; however, in practice the net result was often more civil war. Although in political reality

adoption Adoption is a process whereby a person assumes the parenting of another, usually a child, from that person's biological or legal parent or parents. Legal adoptions permanently transfer all rights and responsibilities, along with filiation, fro ...

was an alternative technique to aim for the same result in terms of succession (and which succeeded in producing one genealogically "false" but politically satisfactory dynasty of so-called " Adoptive Emperors"), constitutionally, this was a horror as the Republic had never been abandoned in law. Thus, monarchical succession in the

Principate The Principate was the form of imperial government of the Roman Empire from the beginning of the reign of Augustus in 27 BC to the end of the Crisis of the Third Century in AD 284, after which it evolved into the Dominate. The principate was ch ...

, however realistic, was officially out of the question, and this stigma persisted in the Dominate, despite the obviously monarchical trappings adopted by the emperors in this era. 'Designation', rather than simple adoption, could at least be justified by qualitative criteria.

Roman consortia imperii

* An early case of one emperor, remaining "sole sovereign" in charge but designating one junior and successor, was

Marcus Aurelius Marcus Aurelius Antoninus ( ; ; 26 April 121 – 17 March 180) was Roman emperor from 161 to 180 and a Stoicism, Stoic philosopher. He was a member of the Nerva–Antonine dynasty, the last of the rulers later known as the Five Good Emperors ...

(reigned 161–180 AD), who designated

Lucius Verus Lucius Aurelius Verus (; 15 December 130 – 23 January 169) was Roman emperor from 161 until his death in 169, alongside his adoptive brother Marcus Aurelius. He was a member of the Nerva–Antonine dynasty. Verus' succession together with Ma ...

. * Emperor

Diocletian Diocletian ( ; ; ; 242/245 – 311/312), nicknamed Jovius, was Roman emperor from 284 until his abdication in 305. He was born Diocles to a family of low status in the Roman province of Dalmatia (Roman province), Dalmatia. As with other Illyri ...

attempted an elaborate system with four emperors (two seniors styled

Augustus Gaius Julius Caesar Augustus (born Gaius Octavius; 23 September 63 BC – 19 August AD 14), also known as Octavian (), was the founder of the Roman Empire, who reigned as the first Roman emperor from 27 BC until his death in A ...

, each with a junior styled

Caesar Gaius Julius Caesar (12 or 13 July 100 BC – 15 March 44 BC) was a Roman general and statesman. A member of the First Triumvirate, Caesar led the Roman armies in the Gallic Wars before defeating his political rival Pompey in a civil war. He ...

), called later the

Tetrarchy The Tetrarchy was the system instituted by Roman emperor Diocletian in 293 AD to govern the ancient Roman Empire by dividing it between two emperors, the ''augusti'', and their junior colleagues and designated successors, the ''caesares''. I ...

. Revolutionary was the notion that each was to be simultaneously in permanent charge of one quarter of the empire, not just sharing in central government. The experiment did not live up to its promise, as succession was not smoothened but contention multiplied, so the quadruple emperorship was abandoned—not the quarters, which remained as administrative and military divisions called

praetorian prefecture The praetorian prefecture (; in Ancient Greek, Greek variously named ) was the largest administrative division of the Late Antiquity, late Roman Empire, above the mid-level Roman diocese, dioceses and the low-level Roman province, provinces. Praeto ...

, as did the lower level, called

diocese In Ecclesiastical polity, church governance, a diocese or bishopric is the ecclesiastical district under the jurisdiction of a bishop. History In the later organization of the Roman Empire, the increasingly subdivided Roman province, prov ...

, and the smaller size (and larger number) of

Roman province The Roman provinces (, pl. ) were the administrative regions of Ancient Rome outside Roman Italy that were controlled by the Romans under the Roman Republic and later the Roman Empire. Each province was ruled by a Roman appointed as Roman g ...

s. * In 395, the Roman Empire was split for good, but in two halves:

Western Western may refer to: Places *Western, Nebraska, a village in the US *Western, New York, a town in the US *Western Creek, Tasmania, a locality in Australia *Western Junction, Tasmania, a locality in Australia *Western world, countries that id ...

and Eastern, each under a sovereign emperor, in charge of two praetorian prefectures, each with or without a partner in government. * Both the notion of "partnership" in the form of a senior emperor and several junior co-emperors (usually, but not necessarily, his sons), and Diocletian's titulature, but mainly versed in Greek (e.g. ''

Sebastos ( , ) was an honorific used by the ancient Greeks to render the Roman imperial title of . The female form of the title was (). It was revived as an honorific in the 11th century Byzantine Empire and came to form the basis of a new system of co ...

'' for ''

'', a literal translation), became quite common in the

Eastern Roman Empire The Byzantine Empire, also known as the Eastern Roman Empire, was the continuation of the Roman Empire centred on Constantinople during late antiquity and the Middle Ages. Having survived the events that caused the fall of the Western Roman E ...

, i.e. Byzantium, which lasted a further millennium after the fall of the Western Empire.

References

Heads of state Government of the Roman Empire Roman Empire in late antiquity Latin political words and phrases Power sharing

Roman consortia imperii

See also

References