Instruct: Given a question, retrieve passages that answer the question.
Query: Who was the first emperor of the Roman Empire?
The Roman emperors were rulers of the Roman Empire, wielding power over its citizens and military, dating from the granting of the title of Augustus to Gaius Julius Caesar Octavianus by the Roman Senate in 27 BC. Augustus maintained a façade of republican rule, rejecting monarchical titles but calling himself princeps senatus (first man of the senate)[1] and princeps civitatis (first citizen of the state). The title of Augustus was conferred on his successors to the imperial position. The style of government instituted by Augustus is called the Principate and continued until reforms by Diocletian. The modern word 'emperor' derives from the title imperator, which was granted by an army to a successful general; during the initial phase of the empire, it still had to be earned by the princeps.
During the Crisis of the Third Century, from 260 to 274, Gaul was subject to Alamanni raids because of the civil war. In reaction to local problems the Gallo-Romans appointed their own emperor Postumus. The rule over Gaul, Britannia, and Hispania by Postumus and his successors is usually called "The Gallic Empire" although it was just one set of many usurpers who took over parts of the Roman Empire and tried to become emperor. The capital was Trier which was often used as the northern capital of the Roman Empire by many emperors. The Gallic Empire ended when Aurelian decisively defeated Tetricus I at Chalons.
Francis II (; 12 February 1768 – 2 March 1835) was the last Holy Roman Emperor, ruling from 1792 until 6 August 1806, when he dissolved the Holy Roman Empire of the German Nation after the decisive defeat at the hands of the First French Empire led by Napoleon at the Battle of Austerlitz. In 1804, he had founded the Austrian Empire and became Francis I, the first Emperor of Austria, ruling from 1804 to 1835, so later he was named the one and only "Doppelkaiser" (double emperor) in history.
For the two years between 1804 and 1806, Francis used the title and style "by the Grace of God elected Roman Emperor, ever Augustus, hereditary Emperor of Austria" and he was called the "Emperor of both the Holy Roman Empire and Austria". He was also Apostolic King of Hungary and Bohemia as Francis I. He also served as the first president of the German Confederation following its establishment in 1815.
Diocletian divided the empire into four regions, each ruled by a separate emperor, the Tetrarchy. Confident that he fixed the disorders that were plaguing Rome, he abdicated along with his co-emperor, and the Tetrarchy soon collapsed. Order was eventually restored by Constantine the Great, who became the first emperor to convert to Christianity, and who established Constantinople as the new capital of the eastern empire. During the decades of the Constantinian and Valentinian dynasties, the empire was divided along an east–west axis, with dual power centres in Constantinople and Rome. The reign of Julian, who under the influence of his adviser Mardonius attempted to restore Classical Roman and Hellenistic religion, only briefly interrupted the succession of Christian emperors. Theodosius I, the last emperor to rule over both East and West, died in 395 AD after making Christianity the official religion of the empire.
The Latin Empire (official Empire of Romania) was a Crusader state founded after the Fourth Crusade on lands captured from the Eastern Roman (Byzantine) Empire. The Latin Empire was intended to supplant the Byzantine Empire as the titular Roman Empire in the east, with a Western Roman Catholic emperor enthroned in place of the Eastern Orthodox Roman emperors. James of Baux willed his titular claims to Duke Louis I of Anjou, also claimant to the throne of Naples, but Louis and his descendants (including the Holy Roman Emperor from the House of Habsburg-Lorraine and the Austrian emperors through Francis I) never used the title.
The legal and civic status of the Jews underwent a transformation under the Holy Roman Empire. Jewish people found a certain degree of protection with the emperor of the Holy Roman Empire, who claimed the right of possession and protection of all the Jews of the empire. A justification for this claim was that the Holy Roman Emperor was the successor of the emperor Titus, who was said to have acquired the Jews as his private property. The German emperors apparently claimed this right of possession more for the sake of taxing the Jews than of protecting them.
Roman expansion began long before the state was changed into an Empire and reached its zenith under emperor Trajan with the conquest of Mesopotamia and Armenia in AD 113. The period of the "Five Good Emperors" saw a successions of peaceful years and the Empire was prosperous. Each emperor of this period was adopted by his predecessor. The Nerva–Antonine dynasty was a dynasty of seven consecutive Roman Emperors who ruled over the Roman Empire from 96 to 192. These Emperors are Nerva, Trajan, Hadrian, Antoninus Pius, Marcus Aurelius, Lucius Verus, and Commodus.
The last two of the "Five Good Emperors" and Commodus are also called Antonines. After his accession, Nerva, who succeeded Domitian, set a new tone: he restored much confiscated property and involved the Roman Senate in his rule. Starting in 101, Trajan undertook two military campaigns against the gold rich Dacia, which he finally conquered in 106 (see Trajan's Dacian Wars). In 112, Trajan marched on Armenia and annexed it to the Roman Empire. Then he turned south into Parthia, taking several cities before declaring Mesopotamia a new province of the empire, and lamenting that he was too old to follow in the steps of Alexander the Great. During his rule, the Roman Empire expanded to its largest extent, and would never again advance so far to the east. Hadrian's reign was marked by a general lack of major military conflicts, but he had to defend the vast territories that Trajan had acquired.
The Senate of the Roman Empire was a political institution in the ancient Roman Empire. 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 technically 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. As such, membership in the Senate became sought after by individuals seeking prestige and social standing, rather than actual authority. During the reigns of the first Emperors, legislative, judicial, and electoral powers were all transferred from the "Roman assemblies" to the Senate. However, since the control that the Emperor held over the senate was absolute, the Senate acted as a vehicle through which the Emperor exercised his autocratic powers.
In 1804, Napoleon Bonaparte declared the First French Empire. In response to this, Holy Roman Emperor Francis II of the Habsburg dynasty declared his personal domain to be the Austrian Empire and became Francis I of Austria. Taking the colours of the banner of the Holy Roman Emperor, the flag of the Austrian Empire was black and gold. Francis II was the last Holy Roman Emperor, with Napoleon forcing the empire's dissolution in 1806. After this point, these colours continued to be used as the flag of Austria until 1918.
The chief towns of Upper Moesia (and wider) were: Singidunum (Belgrade), Viminacium (now Old Kostolac), Remesiana (now Bela Palanka), Naissos (Niš), and Sirmium (now Sremska Mitrovica), the latter of which served as a Roman capital during the Tetrarchy. Seventeen Roman Emperors were born in the area of modern-day Serbia, second only to contemporary Italy. The most famous of these was Constantine the Great, the first Christian Emperor, who issued an edict ordering religious tolerance throughout the Empire.
When the Roman Empire was divided in 395, most of Serbia remained under the Eastern Roman Empire, while its northwestern parts were included in the Western Roman Empire. By the early 6th century South Slavs, present throughout the Byzantine Empire in large numbers, merged with the native population (Dacians, Illyrians, Thracians) and assimilated them.
In the late 3rd century, after the Crisis of the Third Century, Diocletian formalised and embellished the recent manner of imperial rule, establishing the so-called Dominate period of the Roman Empire. This was characterised by the explicit increase of authority in the person of the Emperor, and the use of the style Dominus Noster ("Our Lord"). The rise of powerful Barbarian tribes along the borders of the empire and the challenge they posed to defense of far-flung borders and unstable imperial succession led Diocletian to divide the administration geographically of the Empire in 286 with a co-Augustus. In 330, Constantine the Great established a second capital in Byzantium, which he renamed Constantinople. For most of the period from 286 to 480, there was more than one recognised senior emperor, with the division usually based in geographic terms. This division was consistently in place after the death of Theodosius I in 395, which historians have dated as the division between the Western Roman Empire and the Eastern Roman Empire.[2] However, formally the Empire remained a single polity, with separate co-emperors in the separate courts. The fall of the Western Roman Empire, and so the end of a separate list of emperors below, is dated either from the de facto date of 476 when Romulus Augustulus was deposed by Odoacer who became King of Italy, or the de jure date of 480, on the death of Julius Nepos, when Eastern Emperor Zeno ended recognition of a separate Western court. In the period that followed, the Empire is usually treated by historians as the Byzantine Empire governed by the Byzantine Emperors, although this designation is not used universally, and continues to be a subject of specialist debate today.[3]
The Byzantine Empire was the direct legal continuation of the eastern half of the Roman Empire following the division of the Roman Empire in 395. As such, the Byzantine Emperors continued to style themselves as "Roman Emperors", the term "Byzantine" being coined by Western historiography in the 16th century, long after the Empire had fallen. By the time of the Fourth Crusade, the standard title used by the Byzantine ruler was "[Name] in Christ the God, faithful Emperor and Autocrat of the Romans" (in Greek: ). This title was adopted by the Emperors of both Nicaea and Trebizond in 1204 following the establishment of the Latin Empire, and by the short-lived Empire of Thessalonica in 1225, becoming rival claimants to the Roman imperial title.
In 1804, Napoleon Bonaparte declared the First French Empire. In response to this, Emperor Francis II of the Habsburg dynasty declared his personal domain to be the Austrian Empire and became Francis I of Austria. Taking the colours of the banner of the Holy Roman Emperor, the flag of the Austrian Empire was black and gold. Francis II was the last Holy Roman Emperor, with Napoleon forcing the empire's dissolution in 1806. After this point, these colours continued to be used as the flag of Austria until 1918.
After the Fall of Constantinople, having conquered the Byzantine Empire, Mehmed took the title "Kayser-i Rûm", claiming succession to the Roman imperium. His claim was that by possession of the city, he was emperor, a new dynast by conquest, as had happened previously in the Empire’s history. Contemporary scholar George of Trebizond wrote "the seat of the Roman Empire is Constantinople ... and he who is and remains Emperor of the Romans is also the Emperor of the whole world". 
Disunion in the Roman Empire contributed to disunion in the Church. Theodosius the Great, who in 380 established Nicene Christianity as the official religion of the Roman Empire (see Edict of Thessalonica), was the last Emperor to rule over a united Roman Empire. Following the death of Theodosius in 395, the Empire was divided for the final time into western and eastern halves. In the 4th century, the Roman emperor (reigning in Constantinople) started to control the Church in his territory.
Following the end of the Eastern Roman Empire after the Fall of Constantinople in 1453 and the dissolution of the Holy Roman Empire in 1806, the title of "Emperor" became widespread among European monarchs. The Austrian Empire laid claim to be the heir of the Holy Roman Empire as Austria's Habsburgs attempted to unite Germany under their rule. The German Empire, established in 1871, also claimed to be a successor of Rome through the lineage of the Holy Roman Empire. Both of these empires used the imperial title "Kaiser" (derived from the Latin word "Caesar"), the German word for emperor. The German Empire and Austria-Hungary, successor of the Austrian Empire, would both fall in the aftermath of the First World War along with the Russian and Ottoman Empires who had both claimed succession from the Eastern Roman Empire.
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.
Cniva ( mid-3rd century AD) was a Gothic chieftain who invaded the Roman Empire. He successfully captured the city of Philippopolis (Plovdiv in Bulgaria) in 250 and killed Emperor Decius and his son Herennius Etruscus at the Battle of Abritus as he was attempting to leave the Empire in 251. This was the first time a Roman Emperor had been killed in combat against barbarians. He was allowed by the new Emperor Trebonianus Gallus to leave with his spoils and was paid tribute to stay out of the empire.
In addition to remaining as a concept for an administrative unit in the remaining Empire, the ideal of the Roman Empire as a mighty Christian Empire with a single ruler further continued to appeal to many powerful rulers in western Europe. With the papal coronation of Charlemagne as "Emperor of the Romans" in 800 AD, his realm was explicitly proclaimed as a restoration of the Roman Empire in Western Europe under the concept of "translatio imperii". Though the Carolingian Empire collapsed in 888 and Berengar, the last "Emperor" claiming succession from Charlemagne, died in 924, the concept of a papacy- and Germanic-based Roman Empire in the West would resurface in the form of the Holy Roman Empire in 962. The Holy Roman Emperors would uphold the notion that they had inherited the supreme power and prestige of the Roman Emperors of old until the downfall of the Holy Roman Empire in 1806.
Concordat of Worms Emperor for other uses of the title "Emperor" in Europe. First Council of the Lateran Holy Roman Emperors family tree Holy Roman Empress King of the Romans List of German monarchs Holy Roman Empire King of Italy Kingdom of Italy (Holy Roman Empire)
Disunion in the Roman Empire further contributed to disunion in the Church. Emperor Diocletian divided the administration of the eastern and western portions of the empire in the early 4th century, though subsequent leaders (including Constantine) aspired to and sometimes gained control of both regions. Theodosius I, who established Christianity as the official religion of the Roman Empire, died in 395 and was the last emperor to rule over a united Roman Empire; following his death, the division into western and eastern halves, each under its own emperor, became permanent. By the end of the 5th century, the Western Roman Empire had been overrun by the Germanic tribes, while the Eastern Roman Empire (known also as the Byzantine Empire) continued to thrive. Thus, the political unity of the Roman Empire was the first to fall.
The authority of Julius Nepos as Emperor was accepted not only by Odoacer in Italy, but by the Eastern Empire and Syagrius in Gaul (who had not recognized Romulus Augustulus). Nepos was murdered by his own soldiers in 480, a plot some attribute to Odoacer or the previous, deposed emperor Glycerius, and the Eastern Emperor Zeno chose not to appoint a new western emperor. Zeno, recognizing that no true Roman control remained over the territories legally governed by the Western court, instead chose to abolish the juridical division of the position of Emperor and declared himself the sole emperor of the Roman Empire. Zeno became the first sole Roman emperor since the division after Theodosius I, 85 years prior, and the position would never again be divided. As such, the (eastern) Roman emperors after 480 are the successors of the western ones, albeit only in a juridical sense. These emperors would continue to rule the Roman Empire until the Fall of Constantinople in 1453, nearly a thousand years later. As 480 marks the end of the juridical division of the empire into two separate imperial courts, some historians refer to the death of Nepos and abolition of the Western Empire by Zeno as the end of the Western Roman Empire.
Diocletian divided the empire into four regions, each ruled by a separate Emperor (the Tetrarchy). Confident that he fixed the disorders plaguing Rome, he abdicated along with his co-emperor, and the Tetrarchy soon collapsed. Order was eventually restored by Constantine, who became the first emperor to convert to Christianity, and who established Constantinople as the new capital of the eastern empire. During the decades of the Constantinian and Valentinian dynasties, the Empire was divided along an east–west axis, with dual power centers in Constantinople and Rome. The reign of Julian, who under the influence of his adviser Mardonius attempted to restore Classical Roman and Hellenistic religion, only briefly interrupted the succession of Christian emperors. Theodosius I, the last emperor to rule over both East and West, died in 395 AD after making Christianity the official religion of the Empire.
Though Marcellinus does not refer to the Empire as a whole after 395, only to its separate parts, he clearly identifies the term "Roman" as applying to the Empire as a whole. When using terms such as "us", "our generals", and "our emperor", Marcellinus distinguished both divisions of the Empire from outside foes such as the Sasanian Persians and the Huns. This view is consistent with the view that contemporary Romans of the 4th and 5th centuries continued to consider the Empire as a single unit, although more often than not with two rulers instead of one. The first time the Empire was divided geographically was during the reign of Diocletian, but there was precedent for multiple emperors. Before Diocletian and the Tetrarchy, there had been a number of periods where there was more than one co-emperor, such as with Caracalla and Geta in 210–211, who inherited the imperial throne from their father Septimius Severus, but Caracalla ruled alone after the murder of his brother.
Charlemagne, and the subsequent Holy Roman Emperors, were not, and did not claim to be, rulers of a restored Western Roman Empire. Pope Leo III and contemporary historians were fully aware of that the notion of a separate Western court had been abolished over three centuries prior and considered the Roman Empire to be "one and indivisible". The ruler of the Roman Empire at the time of Charlemagne's coronation was Irene, the mother of emperor Constantine VI who she had deposed. Leo III considered Irene to be a usurper and illegitimate to rule due to her gender and as such considered the imperial throne to be vacant. Thus, Charlemagne was not crowned as the ruler of the Western Roman Empire and successor to Romulus Augustulus, but rather as the successor of Constantine VI and as sole Roman Emperor. Irene was deposed and replaced by Emperor Nikephoros soon after, and the Eastern Empire refused to recognize the Imperial title of Charlemagne. Following several wars in the 810s Emperor Michael I Rangabe eventually recognized Charlemagne as an "Emperor", but as the slightly humiliating "Emperor of the Franks" rather than "Roman Emperor", a title he reserved for himself. For centuries to come, the "revived" Western court and the Eastern court, in direct succession to the Roman Emperors of old, would make competing claims to be rulers of the whole Roman Empire. With the Eastern Empire terming the Holy Roman Empire as an "Empire of the Franks", the term "Empire of the Greeks" was popularized in the Frankish court as a way to refer to the Empire centered in Constantinople.