. Portraits after the
Tetrarchy stopped including realistic features, as the emperor began to be seen as a symbol rather than an individual. The period after the
Principate is known as the
Dominate, derived from the title
dominus ("lord") adopted by
Diocletian. During his rule, the emperor became an absolute ruler and the regime became even more monarchical. The emperors adopted the
diadem crown as their supreme symbol of power, abandoning the subtleties of the early Empire. Beginning in the late 2nd century, the Empire began to suffer a series of political and economic crises, partially because it had overexpanded so much. The
Pax Romana ("Roman peace") is often said to have ended with the tyrannical reign of Commodus. His murder was followed by the accession of
Septimius Severus, the victor of the
Year of the Five Emperors. It was during his reign that the role of the army grew even more, and the emperors' power increasingly depended on it. The murder of his last relative,
Severus Alexander, led to the
Crisis of the Third Century (235–285), a 50-year period that almost saw the end of the Roman Empire. The last vestiges of Republicanism were lost in the ensuing anarchy. In 238, the Senate attempted to regain power by proclaiming
Pupienus and
Balbinus as their own emperors (the first time since
Nerva). They managed to usurp power from
Maximinus Thrax, but they were killed within two months. With the rise of the "soldier emperors", the city and Senate of Rome began to lose importance. Maximinus and
Carus, for example, did not even set foot on the city. He declared himself
Jovius, the son of
Jupiter, and his partner Maximian was declared
Herculius, son of
Hercules. This divine claim was maintained after the rise of Christianity, as emperors regarded themselves as the chosen rulers of God. The emperor no longer needed the Senate to ratify his powers, so he became the sole source of law. These new laws were no longer shared publicly and were often given directly to the
praetorian prefects – originally the emperor's bodyguard, but now the head of the new
praetorian prefectures – or with private officials. The emperor's personal court and administration traveled alongside him, which further made the Senate's role redundant. Consuls continued to be appointed each year, but by this point, it was an office often occupied by the emperor himself, who now had complete control over the bureaucratic apparatus. Diocletian did preserve some Republican traditions, such as the
tribunicia potestas. The last known emperor to have used it was
Anastasius I, at the start of the 6th century. Anastasius was also the last attested emperor to use the traditional titles of
proconsul and
pater patriae. The last attested emperor to use the title of consul was
Constans II, who was also the last Eastern emperor to visit Rome. It's possible that later emperors also used it as an honorary title, as the office of consul was not
abolished until 892, during the reign of
Leo VI. During the Dominate it became increasingly common for emperors to raise their children directly to
augustus (emperor) instead of
caesar (heir), probably because of the failure of the Tetrarchy. This practice had first been applied by
Septimius Severus, who proclaimed his 10-year-old son
Caracalla as
augustus. He was followed by
Macrinus, who did the same with his 9-year-old son
Diadumenian, and several other emperors during the Crisis. This became even more common from the 4th century onwards.
Gratian was proclaimed emperor at the age of 8, and his co-ruler and successor
Valentinian II was proclaimed emperor at the age of 4. Many child emperors such as
Philip II or
Diadumenian never succeeded their fathers. These co-emperors all had the same honors as their senior counterpart, but they did not share the actual government, hence why junior co-emperors are usually not counted as real emperors by modern or ancient historians. There was no title to denote the "junior" emperor; writers used the vague terms of "second" or "little emperor". Despite having a successful reign himself, Diocletian's tetrarchic system
collapsed as soon as he retired in 305.
Constantine I, the son of tetrarch
Constantius I, reunited the empire in 324 and imposed the principle of hereditary succession, which Diocletian intended to avoid. Constantine was also the first emperor to convert to
Christianity, and emperors after him, especially after its officialization under
Theodosius I, saw themselves as the protectors of the Church. The territorial divisions of the Tetrarchy were maintained, and for most of the following century the Empire was ruled by two senior emperors, one in the West (with
Milan and later
Ravenna as capital) and another in the East (with
Constantinople as capital). This division became permanent on the death of
Theodosius I in 395, when he was succeeded by his sons
Honorius and
Arcadius. The two halves of the Empire, while later functioning as
de facto separate entities, were always considered and seen, legally and politically, as separate administrative divisions of a single, insoluble state by the Romans of the time. In the
West, the office of emperor soon degenerated into being little more than a puppet of Germanic
generals such as
Aetius and
Ricimer; the last emperors of the West being known as the "shadow emperor". In 476, the
Heruli Odoacer overthrew the child-emperor
Romulus Augustulus, made himself
king of Italy and shipped the imperial regalia to the
Emperor Zeno in Constantinople. Historians mark this date as the date of the
fall of the Western Roman Empire, although by this time there was no longer any "Empire" left, as its territory had reduced to Italy.
Julius Nepos, who was overthrown and expelled to
Dalmatia in favor of Romulus, continued to claim the title until his murder in 480. The Eastern court recognized this claim and Odoacer minted coins in his name, although he never managed to exercise real power. The death of Nepos left
Zeno as the sole emperor of a (technically) reunited Roman Empire.
Byzantine period The Roman Empire survived in the East for another 1000 years, but the marginalization of the former heartland of Italy to the empire had a profound cultural impact on the empire and its emperor, which adopted a more
Hellenistic character. The Eastern emperors continued to be recognized in the
Western kingdoms until the accession of
Irene (), the first
empress regnant. The Italian heartland was recovered during the reign of
Justinian I (), but this was reverted by the end of the century. Rome technically remained
under imperial control, but was completely surrounded by the
Lombards. Africa was
lost to the Arabs in the early 7th century, and Rome eventually fell to the Lombards in 751, during the reign of
Constantine V. The Frankish king
Pepin the Short defeated them and received the favour of
Pope Stephen II, who became the head of the
Papal States. Pepin's son,
Charlemagne, was crowned
Imperator Romanorum (the first time
Imperator was used as an actual regnal title) by
Pope Leo III in Christmas AD 800, thus ending the recognition of the Eastern emperor. Western rulers also began referring to the Empire as the "Greek Empire", regarding themselves as the true successors of Rome. and his family, 1404. The inhabitants of the Eastern half of the Empire always saw the emperor as an open monarch. Starting with
Heraclius in 629, Roman emperors styled themselves "
basileus", the traditional title for Greek monarchs used since the times of
Alexander the Great. The title was used since the early days of the Empire and became the common imperial title by the 3rd century, but did not appear in official documents until the 7th century.
Michael I Rangabe () was the first emperor to actually use the title of "Roman emperor" (,
Basileus Romaíon). This was a response to the new line of emperors created by Charlemagnealthough he was recognized as
basileus of the
Franks. By the 9th century the full imperial title became "
basileus and
autokrator of the Romans", usually translated as "Emperor and Autocrat of the Romans". The title
autokrator was also used to distinguish a junior co-emperor (
basileus) from his senior colleague (
basileus autokrator). By the times of the
Palaiologos, there were two distinct ceremonies for the accession of an emperor: first an acclamation as
basileus, and later a
coronation as
autokrator (which also included being raised on a shield). These rites could happen years apart. The Eastern Empire became not only an
absolute monarchy but also a
theocracy. According to
George Ostrogorsky, "the absolute power of the Roman emperor was further increased with the advent of Christian ideas". This became more evident after the
Muslim conquests of the 7th century, which gave Byzantine imperialism a new sense of purpose. The emperor was the subject of a series of rites and ceremonies, including a
formal coronation performed by the
Patriarch of Constantinople. The line of Eastern emperors continued uninterrupted until the
sack of Constantinople and the establishment of the
Latin Empire in 1204. This led to the creation of three lines of emperors in exile: the
emperors of Nicaea, the
emperors of Trebizond, and the short-lived
emperors of Thessalonica. The Nicean rulers have been traditionally regarded as the "legitimate" emperors of this period, as they recovered Constantinople and restored the Empire in 1261. The
Empire of Trebizond continued to exist for another 200 years, but from 1282 onwards its rulers used the modified title of "Emperor and Autocrat of all the East,
the Iberians, and the
Perateia", accepting the Niceans as the sole Roman emperors. However, the Byzantine Empire had been reduced mostly to Constantinople, and the rise of other powers such as
Serbia and
Bulgaria forced the Byzantines to recognize their rulers as
basileus. Despite this, emperors continued to view themselves as the rulers of an "universal empire". Constantinople finally
fell to the Ottoman Turks in 1453; its last emperor,
Constantine XI Palaiologos, died in battle. The last vestiges of the empire,
Morea and
Trebizond, fell in 1461. ==Titles==